Brighton would be as good a choice you can make as a stepping stone if he’s trying to get to United down the line. He gets to “prove himself” in the same league, settle in the same country, play in a team that doesn’t park the bus, and for a club that most likely won’t price him out of a future big move (as opposed to clubs like West Ham/Leicester/Villa/Everton).
If all his quotes we read throughout this saga are true (that he wants to get to United but only when he’s ready) then I wouldn’t rule out the possibility that we were in for him but he wanted to take a smaller step first. If that is the case then fair play to the lad, he’s got some balls.