a number of people seem to think that MWI means that any world you can verbally describe exists somewhere, rather than just worlds that have split off from quantum events. No, there is not necessarily a world out there in which the Nazis won WWII.

But all but the most fundamental (e.g. particle masses) asymmetry/"randomness" in the world comes from quantum events, no? Which would imply that every physically possible world (up to the size of the universe, if it's finite) exists in the wavefunction under a pretty broad definition of "physically possible", including Nazi victories and simulations of all physically impossible but logically possible worlds.