I think even though Manchester United have won the FA trophy now, it doesn't mean they are a good enough team at the moment, to face next season of course Manchester United need to improve their performance and also their mentality to achieve consistency in the matches they will indeed live next season, reportedly Manchester United are currently evaluating Ten Hag and let's wait what they will decide later.
Aside from the issue of manager, Manchester United have a lot of overhauling to do. A team like Manchester United shouldn't have the kind of players they have in their squad. There is no way they'll be able to compete against the top teams in Europe with a squad like that.
I have never hidden were I stand with Ten Hag, I believe he won't be a good coach for Man United and he should be replaced, but we also have to consider the squad of his team. The team lacks good defenders and midfielders, even the attack is not very good.
I understand that the squad cannot be strengthened in one transfer window, but there should be a plan. If a new manager is taking over or Man United is sticking with Ten Hag, there should be a plan on how to have a world class squad in the next 2 seasons.