It's true. Then there are also the skeletons. But maybe they're NPCs that have changed? I don't know. The theory of the astral plane makes sense, but then I think about Orion's ability. If the plane is astral, how can he enter it with his real body?
But even here, a thousand possibilities come into play. The only difference I notice, and it's the most relevant in my opinion, is the lack of populations between the servers and Earth and the elven world, which in the past was populated by both humans and elves.
But after listening to the conversations between Orion and Calypso, it seems that there are no more humans in her world, since the young elf ends up mistaking him for a monkey? (I don't remember well.)
It can be deduced that either the two peoples no longer have contact, or the humans for some reason are no longer in her world. (Maybe they went to Earth, which as you said could be another server?) Here your theory could find confirmation.
