The rumours about Pokemon Switch only suggest that 1) there will some kind of integration with Pokemon Go, and 2) Pokemon Go will influence the catching mechanics. I'm not sure where the idea that the battle system would see a significant change or that these games wouldn't even really be RPGs is coming from. Game Freak doesn't make Pokemon spin-offs, so this is almost certainly a main Pokemon game even if it's not Gen 8, and I doubt they're going to abandon the core battle system that has been in the series from its inception (even for a one-off). I think people might be reading a little too much into the Pokemon Go angle. There are plenty of ways of integrating it without changing the core structure of the main Pokemon games.