The chances of him breaking through at either are very slim. Personally, I'd assume he's banking on being more likely to get chances because of his "former Man Utd" status than if he had "only" come through our academy. I think the perception around our academy has already changed and is now very strong, but I don't think there will ever come a time that players coming out of Man Utd won't be fashionable and won't be given more chances than most to succeed.
Yes, it might make it easier for him when he goes in loan, coming from a 'big club'. Rather like the contrast at Middlesbrough between the way the fans have partly taken to Balogun (a star prospect from the mighty Arsenal) whilst deciding that Connolly is the worst player ever to play for Mddlesbrough (yes, that view has been expressed on their website) even though he has contributed more to the team than Balogun (not that he's doing great by any means, but he's not been that bad either).