Yes, I think usually access is perpetual, just as it would have been had the library had a physical copy. For new issues, I'm confident people will manage; as

Yes, I think usually access is perpetual, just as it would have been had the library had a physical copy. For new issues, I'm confident people will manage; as you say, preprints have taken root in many more disciplines, and there are plenty of alternatives - legal ones, like inter-library loan, and Sci-Hub.