Can some shelter cats not adapt to being indoor only ? ?

A cat is like a child, yeah they complain about not being able to stay out late, but in the long run, its best for them. Safety comes first with kids as well with pets. Your cat will meow at the door for a while, but he will get over it, and he will live longer. A cat is a very domestic animal and it will adjust. Make sure it has plenty of entertainment and attention and all will be well. Your story is a great example of the number 1 reason all cats should be indoors, if you love them!