Boats broken and all mobs exit boats when updated to 1.20 versions

All mobs exit boats, not just the ones that are too big. This also only affects the worlds imported to the Preview, not worlds imported/exported around the base game. 

 

Correction: this affects many versions, not just the ones in the preview. If you have mobs in boats, especially discontinued ones, like spiders, polar bears, Hoglins, etc, DO NOT OPEN YOUR WORLDS. I only hope this bug is fixed soon.