>>22779861Yes there is. Unless you want to say that every universe is a part of the multiverse then it's not proven. Hell by your logic the digimon universe can be a alternative canon universe.
If you're going to say that there is infinite number of universes then there is no pokeverse either, it's just a subcategory of all universes on could think of across all medias, franchises and what not.
There is only one alternative universe stright up mentioned in the games, and that's a universe where the ultimate weapon was not fired.
Anoter(or the same) was hinted at by Archie/Maxie were they were the bad guys, but that was more just speaking their minds because their motives and actions were quite a like, and a reference.
It's a far shot to say that all pokémon medias are part of the game multiverse. All it would take to disprove that would be a single manga-adaption stating that it only has one universe and that's that.