One thing I will say is that every single Manchester United goalkeeper in my living memory, going all the way back to Peter Schmeichel, bar maybe Edwin van der Sar, has had a very shaky start to their career.
Schmeichel was all over the place under the high-ball. De Gea made several errors. Howard and Carroll took it in turns to drop a clanger each weekend. Onana has never stopped dropping clangers. Bayindir belongs with Taibi in the 'comedy' bracket. Barthez seemed desperate to create mistakes out of nothing. Bosnich never looked like a United goalkeeper.
Point is, this kid will definitely, 100% make a mistake in his first few games because of the pressure of being a United goalkeeper. And if he doesn't, the media will pretend he did anyway. We'll have lads smashing them into the top corner from 10y and Gary Neville and the like will be saying "the goalkeeper could do better there for me".
Please don't fall for the ragebaiting. Young lad coming from a much weaker league, give him some time to develop