Yes indeed, at the beginning we can only predict whether Mason Mount will succeed or not, of course we will not be able to confirm it at this time. Because after all, using an iconic number at Manchester United is also not always the right choice, among which has been proven by the existence of several players who failed to make a good contribution to Manchester United like the player you mentioned. But yes, even so we should give Mason Mount full trust and support, because it can also make Mason Mount able to play with good confidence.
Mason Mount, one of Chelsea's significant players and likely a key project under Erik Ten Hag, I believe, will make the difference. Manchester United giving the new player jersey number 7, I'm not sure what they're expecting. We all know that individuals who donned the number 7 jersey don't always function effectively at Old Trafford; they may thrive one season and then struggle the following. As an illustration, Angel Di marria, Memphis Depay, and Alexis Sanchez all failed, with the exception of Cristiano Ronaldo, the uncontested possessor of the legendary number.