It seems that Bayern Munich is only planning to add another goalkeeper in the short term. Yann Sommer is 34 years old, as is Sven Ulreich. So it seems that Bayern Munich assume that Neuer will be back in the goal next season. I think that Yann Sommer know it too. Therefore, I can not understand why he should change.
A transfer of Livakovic would make more sense.
Yes, a rather strange decision. They started preparing a replacement for Lewandowski in about 2 years of his alleged decline in the level of play, and with Neuer they act as if they are waiting for him to play at the top level for another 10 years. Maybe it will really be an emergency short-term decision and strategic decisions on the position of the goalkeeper will be made in the summer without haste.