Honestly, I'd rather have Iris than May, Dawn, and Serena combined if I can't have Misty. At least Iris wasn't used as explicit fanservice despite being grossly underage, unlike May, Dawn, or possibly even Serena (and believe me, Masamitsu Hidaka MORE than made clear that that was the sole reason May and Dawn at least existed in the anime in the first place).
And as far as Alola, the prior sagas at least alluded to a league nearing the start of the saga, generally right before the first gym battle. So no, if they wanted an Alola League, they would have mentioned it by now. Instead, as far as we can tell, he's still going to school. Even Best Wishes had Ash learning about a Pokemon League there, and he didn't even originally intend to compete there, just go on a vacation with his mom.
And his Unova team already got quite a bit of attention as it is. Who do you THINK Ash used during Unova?