I think that in this case an injury is not something that is difficult for Bayern to overcome, especially now that they are also preparing to look for options when Neuer is confirmed to be out for the next 3 months.
The problem in the Bundesliga actually lies not in injuries or anything, but in fact it is the differences in the strength of the clubs that have an effect.
Currently Bayern is always on top and that is quite natural because they are at a different level so it is very difficult for other clubs to balance their dominance so inevitably the hegemony will continue.
It is obvious that we are going to end up seeing Bayern eventually start looking not just a replacement for time being, but a long term replacement as well. They probably had some players in mind before and they will look to get those younger players now.
This way not only those goalkeepers will play until Neuer is back, but also they could play together with Neuer when he comes back and learn from him and then they would just bench Neuer and use the younger one. Look at PSG, did they use donnaruma as soon as he got in? Of course not, they kept Navas in for a long time and gradually and slowly replaced him with donnaruma, same logic could happen here.
But this is something different, Bayern Munich have completely lost Manuel Neuer and are out injured, forcing them to use their new keeper. They are serious about bringing in goalkeepers, it can be seen that the names they have chosen are the best goalkeepers from the countries participating in the World Cup. This gives a signal that what they are looking for right now is a goalkeeper who is ready to become the main goalkeeper in the team to replace Manuel Neuer who has to be sidelined due to an injury he has experienced.