Did he?
He chose Real over PSG, but they wanted to give up 20M max for him. When he got that info, he reached back to PSG and PSG said no (and Lille asked for more from them) because he chose Real over them.
United was the only big team left. That's the reason they signed him.
He's IMO the best CB youngster in the world and it's a pity he's now developping in somewhat toxic environment. I was happy to see ETH gone, but even then it's hardly ideal. At least he can toughen up mentally in such a situation, but he's still awfully young to deal with this crap.