So I just got off the phone with MPSC, and they said that not only would they not give me a courtesy bump to Gold based on confirmed travel, but that I would also not become Gold until I completed the round trip itinerary, at which time I would go straight to Platinum.

That seems a bit odd to me, so perhaps something got lost in translation (I was clearly talking to a remote call center). Not sure it's entirely worth HUCA, since I'm pretty sure even United's computers can figure out a Premier status change in less than a week. All I'd be giving up is the complimentary bump to Gold, which I wasn't expecting or counting on in the first place.