Phil in Groundhog Day does genuinely transform for the better. The movie shows the difference between when he's just manipulating Andi McDowall's character and when he genuinely loves her. He is only released from his prison when he does genuinely care for others.

Other autistic-coded characters that are interesting to observe are Anya from Buffy (someone literally from another place, who struggles with human customs, but is eventually valued by everyone around her for her courage and decency), and Wednesday from the Netflix series (just because she keeps a neutral expression doesn't mean that she doesn't deeply care for her friends).