The mods that haven’t been updated are causing crashes, yes. Mod authors are working on their updates and many mods have already been updated, more to follow. However, mods that have been abandoned by their mod authors may no longer work after this update unless they get updated to the latest DevKit.
All mods updated today, should be working. There are quite a few already. One thing I suggested in the LBPR discord is the following:
Go to your workshop page, filter your subscribed mods by “date updated”. Everything which was updated 15th+ should be good to go. You can use it, everything that hasn’t been updated is probably going to crash your game, so you have to test these 1 by 1. There is also the problem that once the mods are updated to the new DevKit, some of them may no longer be compatible with mods that haven’t been updated.