As the London devs even said, they are really excited for this new content and performance update, and they asked you to put down your pitchforks.

This is going to be a setback for the modding that has been done, for sure. That is the contract the mod community understands when they build their creations. It's very evident at every step of the way that you are not using consumer grade products with ABI guarantees.

But Bethesda has publicly stated they went out of their way to try to reduce breakage of mods this time compared to the skyrim anniversary version. So we have to wait and see what that means.

But if you want to hold back performance improvements for everyone because a small niche within the modding scene will have to update their mods to work, that's not a reasonable ask.