I don't see Manchester united winning Europa and they might not go far as you think. Have you forgotten that nothing has changes in the club, Ten Hag is still their manager with his worst performance last season. Manchester united performance last season makes them not deserve to play in Europa next season.
Of course as luck was on their side because when it is your lucky day everything will work in your favor to be successful, this was how United got to Europa after winning City on the finals of FA cup. This is why I don't expect much from Ten Hag amd his boys only if he has improved his squad.
Isn't it too early to make assumptions on Manchester United? I'll give you that about the previous season. They had a really bad time. However we never know what happens in a new season.

Ten Hag is currently doing a good thing. He is looking for improving the most problematic area of the squad, defense. They conceded too many goals last season you know. If ten Hag make a big improvement in this weakness and start the new season with a better squad then they can surely be more ambitious in the Europa League as well. But their priority is to be more competitive in the Premier League now.