Yeah, but there as well: are all of these swimmers suddenly the best ever? I know and understand they're good, but it would be an extreme coincidence if in one specific event suddenly a handful of the best ever appear.
It 'smells' way more like either some sort of thing with the pool or some sort of new breakthrough in clothing or something like that, some of the margins with which the records are being smashed are truly insane and seem to go way further than just 'ah, first time she raced in a 25m pool I mean, imagine a 20+ WR world championships in athletics, we'd be desperately looking for explanations (like the super shoes in recent years, so at least there is an explanation there)