Yeah the last episode was better for sure, what the heck Goodra? You came back just to faint? That was ridiculous Goodra should have won that, and I think it's silly to make Greninja so powerful, and have an arc to himself only for him to lose at the League, come on you can do better then that.
I suppose it was only obvious, Ash has never won a league before, although in a way if Ash had won, then Sun & Moon would be completely pointless? Like why go to school or whatever if you are the Champion, screw that. So guess it was better for him to lose here, then go back to Pokemon School to relearn everything (Although his new animation, might as well made Ash the champion and create a new hero), maybe the next gen after S&M Ash will actually win the Pokemon League, since he pretty much almost won, would have if Alain didn't come,. I like to see that happen, make him learn something at that school. Although without Greninja, he might not bother.