Should I expect caregivers in memory care to form relationships with him and encourage him to leave his room?

One of my biggest fears is to end up in a facility where people pester me and make me do things like make macaroni jewelry or play stupid games. Some people are loners; if that was your dads personality or even if it seems to be more the case now, leave him be.

I got my mom a caregiver that comes in 3 days a week for 4 hours each day. This is self pay. She watches tv with mom, they do laundry and fold, she helps with showers and hair, skin and mouth care. They just talk too. Mom has someone to walk with for exercise and on those walks, they just “happen” to see an activity and mom is happy to see what’s going on. This was after mom spent 14 months on her own with me paying extra for the staff to give her more time. Turns out, she can tell them no and they walk away but they didn’t tell me she was saying no. Moms life is fuller now and having one person she has come to know has been a blessing. One day mom got really sick and I texted the caregiver and told her I was going to get someone to help mom daily until she was better and offered her first right of refusal. She jumped in and took all the days and mom was better in a week. My caregiver doesn’t really want to work more days but she did it because of the relationship and care/concern she has for my mom. If mom moves to locked unit, she will help her there as well. Mom has dementia which is manifested in no reliable short term memory and no concept of self care.

My mom is also hesitant to join activities. She loves the ball game but does not enjoy the other activities. She has always been a shy, solitary soul. She lived on a farm most of her life. In the 43 years she was married, my mom never went out to eat with my father, She does not have good social skills. I am concerned about her isolation but have not tried to force it, I get an angry reaction. She says she is not allowed to choose for herself. My next step is to go with her to one of the activities I think she would enjoy. If I can get her to try it, perhaps she will like it similar to the ball game.

I have learned not to push her. I have to wait for the right moment.

My mom is also a little better than some of the other residents but is frightened by lots of people, loud music and large rooms. Not sure if that is the dementia or a combination of dementia and the characteristics of her life before. She would go days, on the farm, by herself, and was very content.

I cannot make her someone she is not. In my opinion, personality can make a huge impact on their choices.

This is common among many of the higher-functioning residents in an AL. They don't want to join in activities for losts of reasons. Like they don't really have friends in the AL and don't want to participate alone, or because many of the activities seem childish to them and they can be.
A little staff friendliness and encouragement can go a long way too. If your father is content just hanging out in his room reading, then he should be left to it. Would it be possible to hire him a companion a few hours a week to take him out, or to attend some of the activities with him?
Maybe he socializes and has friends that he hangs out with in the evenings when there's less staff around.
I worked in a nice AL a while back. A lot of the residents didn't bother joining in the day time activities.
I worked a few night shifts and let me tell you, that place was jumping. Those old WWII guys used have the party going on in one of their rooms nearly every night. Card games, watching old movies (one guy had a huge flatscreen tv in his room). Those guys always knew where to get a bottle and some snacks and party time. Some of the ladies would show up too.
The AL's regular 2nd-shift worker pretty much stayed in the office watching tv herself and napping. The 3rd-shift lady was just a 'sleep duty' aide so someone was in the building. So the folks who were still able pretty much did whatever they wanted to at night.
These guys rarely left their rooms during the day other than for meals, doctor's appointments, and maybe some occasional daytime drinking down at the VFW. I remember one adult daughter of one of the guys was very concerned that he was lonely and not making friends. I told her don't worry about 'John'. He's the life of the party after hours and explained that afterhours is when these guys socialized.
Could your father maybe be hanging out with some residents after hours too?

My dear SIL, a naturally social person, would often ask at care meetings why my mom was always in her room at the NH. The answer, frankly, was that that was where mom wanted to be. Watching the news, reading the paper, praying her rosary, visiting with the priest or nun who came by weekly.

Mom was never a "joiner".

The staff would explain to us that they couldn't force mom to participate.

My brothers and I didn't worry about this; it was just mom being mom.

My late MIL was in a nursing home for the last several years of her life. In the first year, she steadfastly resisted attending activities, and even when a family member took her to a group activity, she would talk very little and keep her eyes on the floor. One Mother's Day tea, each of us brought her treats from the dessert buffet. She ate nothing. As soon as her WC crossed the threshold to her room, those sweets started to disappear into her mouth. She wouldn't eat in front of 'those old people" even her beloved sweets.
Staff got exasperated at all of their unsuccessful attempts to engage her - and one of them lost patience and described her as 'antisocial' in the hearing of another aide. That worker came back the next day to apologize for what she said. MIL told her it was OK, "I am antisocial, dear."
Pressure to attend group activities was over. 1:1 socializing in her room replaced it, and she enjoyed that.
It all comes down to what his personality was prior to illness, and how he responds to extra attention.

Yes you should, absolutely. It was the policy at mom's MC for all the residents (except those on hospice care) to be dressed by the staff and brought out of their rooms daily by 10 am. They were brought into the main room/activity room to mingle and eat meals, do crafts and activities, watch movies, etc. There they gathered to learn about what was going on that day, too, if there was a trip planned on the mini bus and whether they wanted to go along. The caregivers all encouraged the residents to go out into the garden to relax in the shade, or to go on a walk, or to DO something. The CGs all had a relationship with my mother, ALL of them. Even the temporary people they used from the agencies were instructed to build relationships with the residents. When dementia/AD is at play, it's crucial for the staff to do just that, otherwise, the residents tend to do just what your dad is doing: stay isolated in their rooms all day which is not good for them.

I agree with isthisrealyreal: call a care conference immediately and don't listen to the incessant excuses about being 'short staffed'. We're all SICK TO DEATH of covid excuse #3,452,111. Why are we still PAYING top dollar at these places then, if there's no staff to interact with our folks? Answer that question, executive director!

Best of luck making your voice heard and your expectations known.

Maybe if we ignore COVER99 long enough he will slink away. People literally come here at the end of their ropes, and he makes the silliest comments.

I guess that since you can't really make obscene phone calls anymore, you have to take to the internet for your jollies.

Guess what Cover? NOBODY thinks you're funny.

In regard to the first part of your question, you absolutely should expect caregivers to form relationships with him! Only then will they know if he will be happier left alone or not.
See if you can make regular one-on-one interactions a specific part of his care plan. Have them write out exactly what this will look like and how it will be be ensured this is occurring.
My family has learned the importance of communicating with the right people. Make no assumptions that important information is being communicated to the right people, or that intentions are turned into practice, even at a “fine” facility.

Please investigate a little more into this. The staff may be asking him if he wants to join the group for "____" (fill in the blank). He might be saying no to every opportunity. You may have to develop a plan to get dad to participate in activities he usually enjoys:
Ask staff to stop asking him "yes/ne" questions.
Ask staff to be more proactive in getting him involved... "It's time for..." "Let's give... a try"
Ask dad to "try an activity" for a certain amount of time (10 minutes?) and he can leave after that time if he wishes, The time can be lengthened every week or 2.