I'm going to go ahead and put my final predictions for the league since we'll probably get some spoiler descriptions/titles pretty soon.
I think Ash will lose the league. Looking at clips from the series, I think there's a lot of signs that point to a second place win for Ash.
My heart wants a win, but I think there will be a loss.
THAT BEING SAID THOUGH...
The fact that Gladion had a sigh of relief for winning (
https://serebii.net/anime/pictures/sunmoon/1079ps3.shtml) shows that he was shaken up after the semi-finals. He almost tripped too when Kiawe congratulated him (
https://serebii.net/anime/pictures/sunmoon/1079ps4.shtml) Alain never was really phased or felt "desperate" before his battle with Ash. I believe the only time Alain looked phased was when Ash-Greninja sent out that big old orange thing at him and was forced to quickly command a Blast Burn. So could this mean Ash will overtake Gladio since just the semi-finals shook him up?
Also, having the young professor ask Ash what happens if you win the Pokemon league, and then Ash not saying anything "directly" to his answer his question was humorous, so is that preparing the audience to see what happens when the main character wins the league?
Unless the league gets interupped by TR or TS, we'll know what happens in just a few more weeks!