I am sure Ruben Amorim understands what he has to do to start a new season in the Premier League with Man United, therefore he does not want to get involved with Man United's past because he might fix the players who suit his character and he also has his own coaching system, the players must show their best performance so that the coach can rely on them without having to replace some more players. I think Man United still has a good squad if it is honed well like Ruud can do after Ten Hag left the club.
What Ruben Amorim did was very appropriate because he certainly had analyzed the factors why Manchester United often failed to be consistent every season. Maybe some people will consider Amorim a little selfish for his decision not to involve Ruud van Nistelrooy and a number of staff, but if seen from the positive side Amorim has started a good decision and wants to maximize this opportunity purely under his system.