I think it's very natural, success and failure will always be remembered by everyone, especially Manchester United is a very successful club before. Ten Hag is still part of this season, and it makes sense if fans continue to associate The Red Devils decline with him. Besides, Ruben Amorim also has not managed to fix the chaos inherited by Ten Hag, because of that Ten Hag name is always fresh in the memory. I think next season Ten Hag name will start to fade, with Ruben Amorim starting to overhaul the depth of the Manchester United squad and starting a new era.
The Europa League trophy is quite important for Amorim, at least it will reduce criticism from fans and he can focus more on increasing his confidence. There are many problems faced by Manchester United and maybe a big evaluation is needed next season so that they can be much more solid. Amorim must do his best when facing Lyon in the second leg and victory is a must that needs to be wagered.
The Teh Hag era is over and Amorim must create his own era at Manchester United even though it is still associated now. There needs to be a change in squad depth next season as the current crop of players are not performing consistently.