In the meantime
Sven Ulrich, their second goalkeeper will take over the position of Neuer. Bayern will find one goalkeeper from transfer market because with only two goalkeepers, it is risky. They can get injuries in a second half of season anytime and if both goalkeepers are injured, it's terrible.
Sommer, Livakovic and Emiliano Martinez won't have too expensive price on transfer market.
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.
with Neuer terrible injury Bayern had to issues now, striker and now a good keeper, ever since Lewandowski left to Barcelona, Bayern Munich offensive has not be good. They lack good striker like Lewandowski. And they have not been able to replace him. With the look of thing, Bayern has to do the needful to buy new striker and get a back up keeper till Neuer is back from injury.
Livakovic is good replacement to Neuer if they're able to get him in January.