>>21479045Not him, but I think that Gamefreak wrote the events of their games so players could come to their own conclusion in some instances. They could have easily just said the three Eeveelutions died in the tower, but they didn't. There's connections to be made and that's why people believe they are reincarnated Eeveelutions.
And because this story is open to interpretation, in the end no one can be absolutely right until Gamefreak decides to expand on their story.