Even with programming I would argue you'd be a much better programmer if you can remember more. Obviously sometimes you're going to have to look things up but the more you remember the more problems you'll be able to solve.
Specifically you won't be able to solve a programming problem if the answer requires you combining over 4 things you don't have in your long-term memory (even if you can look them up). This is the main reason why Jeff Dean is a better programmer than me even though we both have access to google - he has more knowledge & experience of programming in his memory than me that means that even though we can both look things up he is able to solve way more problems than me.
Co-pilot slightly changes the type of thing that's valuable to remember, but it doesn't change the importance of remembering things. I think, as you implied, co-pilot probably makes remembering some types of syntax or boilerplate less important.
But does it effect the field like programming? When programming, if I can remember the context, then I can easily search it (research paper, books, documentation, forums etc) Now, with Co-Pilot, isn't it effectively beneficial to understand a topic and develop a general problem solving framework for ourselves so that we can let the AI do it's thing?
What are your opinions regarding it?