It looks like this will just be a rumor because Bayern Munich's management is wiser in making the decision to get a new coach considering that Bayern Munich is a big club in the Bundesliga so they won't be quick to trust a coach who doesn't have much experience.
We all don't know whether Xabi really has intelligence when it comes to managing players or is just lucky, but we'll see and I'm sure Xabi Alonso will prove it after this season to stay at Leverkusen and then pursue a higher title in the Champions League competition.
If later Xabi Alonso succeeds in giving Leverkusen the UEL title, that is an early sign and if in the next season Xabi is able to give Leverkusen achievements in the Champions League, I am sure Bayern Munich will try to get it and for now Bayern Munich will not do that.
Large possibilities for Bayern Munich signing Xavi Hernandez after last confirmed he will leave Barcelona indeed winning the UEFA Champion League tittle in this season, his decision have been final for leaving Barcelona and great opportunity for Bayern if can't sign Xabi Alonso as their first sign priority. I don't think bad with both manager have good reputation right now and success bring their previous teams have quit well performance and waiting which one both of them are large chance for signing.
Xavi Hernandez will be easily manager for signing by bayern Munich because he will be free agent next season, for Alonso seems bit difficult he still has contract left with Leverkusen and many top teams such as Liverpool and Barcelona are interesting with Xabi Alonso.