Ragnick does not seem to me to be the best option for Bayern, although he confirmed that Bayern contacted him, but these were just discussions, and he replied that at the moment he is completely focused on the Austrian national team, and preparing for the Euro. Moreover, he said that even if Bayern makes him an official offer, he is not sure what decision he will make, since he feels very comfortable in the Austrian national team. And besides, he did not achieve anything outstanding at Manchester United, I don’t know what he can give to Bayern.
Even though Ragnick never achieved anything extraordinary while he was with Manchester United, I don't think there's anything wrong with Ragnick accepting the official offer from Bayern Munich. Although I am also not really sure that Ragnick will be able to change Bayern Munich's performance for the better next season, because Bayern Munich needs a coach who has really been tested and has brought a team to become champions in the past. So this might help Bayern Munich a little in changing its performance to be more competitive in the coming season.