If you look at Ten Hag's work with Man United in the past 2 seasons, it can be assumed that Man United has experienced a setback, and I think that reason is enough to get Ten Hag fired. This season Man United has been really bad, and even this is their lowest finish in the Premier League since 1989-90. If Man United continues to trust Ten Hag to handle Man United next season, that would clearly be a big question mark.
As far as I know, Man United has been interested in Thomas Tuchel, and it seems that Tuchel has also given a hint that he is also interested in becoming Man United's coach. But recently a new rumor has emerged, that after being fired by Chelsea, Mauricio Pochettino seems to be linked with Man United.
Ten Hag first season with Man United was indeed quite good because the condition of the players and management were still well organized in carrying out their duties to ensure that the players remained fit and healthy. But if the second season is with Ten Hag, automatically everything involved is under his control, in which case Ten Hag is unable to ensure that the official management works. As a result, the number of injured players which has a negative impact on performance cannot be separated from Man United's poor management. It is no longer well organized and in this case the medical team cannot maintain the players fitness. Easily injured, easily affected on the field due to unstable conditions, plus Ten Hag is bad at providing strategies. During this season, have the Man United players enjoyed their performance on the field? definitely not and it can be seen how unsuitable and stressed the Man United players are when implementing the coach strategy.
It is said that next season Sir Jim will try to improve this, but I wouldn't expect too much because if Ten Hag is still the coach I don't think there will be any changes in a positive direction. It doesn't matter if 1 season is given the opportunity but that way next season Man United will be left behind by other teams.