I think we are going to have to find out what maintenance even looks like when LLMs are involved. "Maintainable" might no longer mean quite the same thing as it used to.
But it's not going to be as easy as "just regenerate everything". There are dependencies external to a particular codebase such as long lived data and external APIs.
I also suspect that the stability of the codebase will still matter, maybe even more so than before. But the way in which we define maintainability will certainly change.