Why would they give you their top tier Platinum status? You are only an Elite, so it would be Gold at best, more likely just Silver. And as noted, unless you show you are moving to the USA, they are reluctant to match from fellow STAR programs. More to the point, given CO's program will end in four months, they are unlikely to even consider a status match. Further, CO and UA don't do straight out matches. You must fly a certain number of miles on their metal flights before the match is granted.

And as I noted earlier, most flights are already filled in C by revenue, miles and SWU upgrades. If you really want to fly C, then fork out another couple of thousand dollars and it's yours!