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 is in a better form than Manchester united and even though United have sacked their coach Eric Ten Hag i don't think it will make much difference in the team because any coach they hire again we need to study the team very well before he can be able to achieve great results because what United needs now is an understanding coach who will take his time to build the team perfectly. Even when Chelsea will meet Manchester united, i can confidently give my prediction to Chelsea to win United. Manchester united will take much time before they can become consistent and win more matches.