Chelsea are doing well currently; we all know that, and if we should follow how Manchester United performance was going before sacking Erik Ten Hag, then I would say we should be expecting Chelsea to beat Manchester United for sure. But since they have a new manager now, we don’t know what type of strategy he will come with,
so we can’t conclude for now till then. But you are right with what you said; if they later fail to do as expected, the criticism on Erik Ten Hag will be in their head again. But let's wait and see what will happen when they meet with Chelsea, but United have a lot of hard work to do to meet up the points.
Chelsea are currently in good form in the Premier League while Manchester United have been very poor this season, they have only recently started to look like a winning team. This match is not an easy one to predict, whether Manchester United changes their coach or not, I believe they always put in their best whenever they play Chelsea, regardless of the coach or tactics. I’m confident that this match will be the start of a new and better era for Manchester United.