Kinda, but keep in mind that nothing is set in stone What we might be seeing now is just the base-form or proto-types of the games' way of organizing them. Though could be like how in Gen 1 all the mons were all over the place lol.
Though yeah keep in mind the demos are just polished up forms of one beta of game or the other so they have SOMETHING to show off, with us probably having a way to see some version exclusives (like trainers having both an oddish AND bellsprout in Red or Blue) vs. like not seeing a form of Deoxys cause it's locked to one version of the other (and if there are VE Alolan variants probably how a majority of them are gonna work. Cause XY had like what 5 version exclusive mega evolutions and yet SM has nada?)
And if you don't believe just look at comments by the creators at E3 of how they had still a ways to go and that their demos they were making were just if anything the games still about beta before gamma (basically with all the lose ends tied up and such.) And while I could see maybe another set of version exclusives UBs, don't think all of them basically are gonna be version exclusives, and even then apparently not all of them are there cause some rumours said there were atleast 10 and I'm only counting 8 from the datamines.
