A lot of assumptions have been made already about the state of things through what has been so far seen. it's been guessed that weather wars might be prominent again because of max moves setting sun/rain/hail/sand among other things like ninetales/pelipper/abomasnow/tyranitar/hippowdon being seen.

There's no reason to assume that hidden abilities will even be available. sun and rain would need to rely on max moves and sunny day/rain dance while hail and sand have auto-generating pokemon. sand teams could very well be the standard meta with two pokemon that serve different niches in a team fitting well together that both start a sandstorm.

I know that this board tends to be anti-meta stuff, but it'd be a problem for vgc doubles and wifi randoms as well. tyranitar would be even more problematic than everyone already says. I dunno, bros. balance seems a little fucked, even more so if HAs are locked.