If an elder didn't like being touched before they had dementia, would they still not like it once diagnoses with the disease?

I think as people with dementia/alz become more childlike, they could very well want physical comfort of some kind. Think of a little kid, how many of them wouldn't like to be rocked and comforted?

They might. It is always okay to test the waters. My father and mother didn't like to be touched. As they are growing old, my father likes being comforted when he is upset with a simple touch. My mother doesn't like it. It depends so much on the person. You can try a simple touch and see what the response is. It might be welcomed.