The match between Galatasaray and Copenhagen will be the key. Man United only has a chance to qualify if the match ends up with a draw. But if it doesn't end up with a draw, Man United has no chance to finish in 2nd place.
Man United might be able to qualify if Copenhagen draws with Galatasaray, but is it possible for Man United to beat Munich, which is said to be the strongest club in the UCL, that is clearly impossible unless Munich underestimates Man United too much and plays their second tier players to help make things easier. Man United will qualify for the next round if in the end Copenhagen and Galatasaray draw.
If I were a Man United supporter, I probably wouldn't really expect them to qualify for the next round even though they managed to win against Munich, they still have a lot to change from their squad and they also need a lot of mature strategies to make Man United ready for the UCL match, to be honest Man United is not very ready for the UCL this season. I'm sure they will fail.