As usual, there's not much to say here, since all the changes to the devfiles will be listed in the main game patch notes.
You're probably safe to start using the new assets in your levels now though, although they may change a bit. If any of them undergo major dimension changes, I'll probably just create a new asset.
Something you might be interested in is that I believe I set the new walls and floors up so that you can set a custom colour for your levels. Let me know if this is something you might want to do and I'll explain how.