Worlds from 20w22a not compatible with update 1.16 pre2

I am trying to boot up a world of mine that has been updated throughout the snapshots of the Nether update. However, after the first pre-release of 1.16, my world has become unplayable. When I click on the backup and load button, the game freezes, and then crashes. As a sidenote, I also noticed that End Gateways do not spawn after defeating the Ender Dragon, even in the pre-releases, as I have not seen a bug fix patchnote related to that issue. Have a good day