Alola's never had a League before, so it would make sense if it's not the exact same as the others.
And why Kiawe can't beat the other trials offscreen?
Because it would be inconsistent with how this series has been done? NONE of the characters have even showed the slightest interest in beating the Kahuna's, except for Kiawe - but he hasn't expressed interest since we saw him beat Olivia in the flashback.
I'm having this sinking suspicion that a bunch of the main cast are just going to get sent invites and that's it. That by every definition would not make it a league, but a tournament.
Agreed, it'd be neat if all the classmates went separate ways after graduation (right before the league) and then they all come back at the league and we get to see them powered up... although i'd also Love to see how they develop, so I'd want to see it all lol.
But NONE of the classmates, bar perhaps Kiawe, have even expressed interest in doing Trials, much less Grand Trials. Lana did the Water Trial
on accident of all things - and probably wouldn't have succeeded if she didn't have Ash's back-up.
It's also very inconsistent with the history of this show. Yes, we've seen Clemont go to Lumiose City to prep, but we haven't seen the main cast of this show go off on their own adventures at all - and it would be bad storytelling and writing to barely develop these characters towards this goal and suddenly have them developed over a timeskip. It would be a slap in the face.
If the anime calls it a league, then it's a league. Whatever you "consider" it.
Yeah, when every series up to this one is going out of their way to have a set system for allowing entry to the tournament, watch this one not have one and be open for all. If all you need to do to enter is show up, then it isn't a league and if the animé wants to pass it off as one, then they've dropped the ball. Not on me, but on them.