Well I think before we can have a conversation about what Pokemon could do with VR, we need to know what kind of VR we're dealing with. Is it just going to be goggles, are there going to be motion controls/full body movement? Because if it's just goggles, it's not going to be that different other than "OMG I can see 360 degrees!", but if they go further with it they could do some interesting things. You could direct your Pokemon's attacks to add more variety to the combat (not only could you choose a Pokemon to target, but you could also target the environment as well to add more strategy perhaps?), you could navigate the overworld more realistically (small ledge blocking your progress, climb it), they could deepen social interactions by allowing you to gesture to other players.
One thing they could do regardless though is hold virtual events. Perhaps tournaments can be conducted virtually and other players can watch them through an in game stadium (ideally they could also include some way to get spectators involved in some way, but short of gambling which is scummy and now illegal, I can't think of a way to do that).
It wouldn't surprise me if a complete VR Pokemon game were in the works right now, honestly. I know that Konami is supposedly working on something similar with Yu-Gi-Oh!, so Pokemon probably isn't too far behind. I'd assume that a VR Pokemon game would be similar to Pokemon GO, but on a whole new level.
I doubt it. The Switch doesn't really have a lot of support for VR RN, there's Labo VR but that's being treated more like a tech demo than a full fledged VR expansion. A VR Pokemon game would most likely be on a future console.
Side note: The first generation games to support VR should be called Fantasy and Reality. The theme fits way too well for them to call it something else.