I don't think so
That comment is really deep and really invites discussion. Now, how to counter your plethora of arguments...
Can Meloetta leave now? Seriously so annoying..
Three weeks... just three more weeks...
...Unless they throw in an OS like they did with the Marowak trainer by making him not show up in the league, then I'd agree.
It is a pointless character regardless of whether or not he appears in the League, which by all intents and purposes he will. He brings nothing to the table in terms of story, he's just there to be there. Kinda like Naoshi in the Sinnoh League. Sure he was established before, but... would it have made any differences if you'd replaced him with any League only character? No. I don't see him being the one to beat Satoshi in the League, I don't see him having any kind of impact on the characters, so yeah... kinda pointless.