Kimmich and Muller will probably not be able to play in the match against Dortmund because of their infection. There are almost no restrictions on Coronavirus anymore, as far as I know. In spite of this, it is still a very big problem, so the players will have to be very careful not to spread the virus from one to another through their contact with each other. In this situation, I think the most sensible decision is obviously going to be for these two players not to play in this match.
But anyway, I will keep Bayern Munich ahead in this matchup regardless of what happens.
Maybe without the presence of Kimmich and Muller will be enough to affect Bayern's performance in the match later, but it seems Nagelsmann has a way to anticipate this problem. as we saw in the champions league match when Bayern were without Muller and Kimmich, but Nagelsmann was able to maximize his squad, even though Viktoria was not a balanced opponent.
on the other hand, this match is an advantage for Dortmund, this match Dortmund will play as the host.
To be sure, Edin Terzic has a mission to break Bayern's dominance over Dortmund. from the H2H history between these two teams, Dortmund have always lost in the last 8 matches. but despite all that, my estimation in this match, Bayern again beat Dortmund with a score of 1-2.