Can be tested by generating a world with any seed up to snapshot version 20w21a and then generate a world with the same seed in version 20w22a. All dungeons generate in different locations

Top part of the image shows a cobblestone-spawner bug. In bottom image, same location but neither dungeon generated, same as all the other dungeons

*Posting because seems like a big change that wasn't mentioned in the snapshot's article so might be unwanted