Kimmich is gradually playing an essential role in the Bayern Munich midfield. However, his performance in recent times has also had some problems. It is unlikely that Kimmich will leave Bayern in the winter transfer, but at the end of the season, it can occur. In fact, Kimmich no longer retains the form to continue playing at the highest level as in previous years because of different injuries. Perhaps coach Thomas Tuchel has found a worthy replacement for the position.
With the class of a star who won the Bundesliga 8 times and the Champions League once, the price of owning Kimmich will certainly not be cheap. MU also faces competition from Liverpool and Barcelona.
As I have said many times, Joshua Kimminch is a man of character and leadership. He has been playing for Bayern Munich for almost 10 years now and he has been performing almost all the time. He was Germany's player of the year a few times. That proves his ability. He is only 28 years old and I believe he has a long way to go. I think Bayern Munich would loss if they don’t renew the contract.
As for his transfer to Manchester United, I would not recommend joining a team which is already suffering. They are suffering to get anything right. Another thing is you know, Ten Hag on the other hand is someone who can not manage the big players. Kimminch is a player of character and I don't think he would be getting along with Ten Hag.
It is very impossible for Kimmich to leave Bayern Munich because it is not a short time for his career at Bayern Munich and he is a candidate for the next captain if Neuer retires later. He is an experienced midfielder that Bayern Munich has and that is why he has never been replaced even during his years at Bayern Munich. Even though Bayern Munich often change coaches, every coach feels he is a leader in the midfield, so there is no hesitation in always placing him in the starting lineup.
Manchester United will only destroy Kimmich's career and it seems he knows that will happen if he joins Manchester United. So the right decision is to reject the offer if there is one and it is also better to continue his professional career at Bayern Munich. However, if he likes challenges outside Germany, it would be better if they come from another big team that has a clear vision and mission to win the title.