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.
After Tuchel has decide to withdraw from his current position as Bayern Munich manager then people has starting to speculate who is the replacement of him but sorry to says i couldn't find any news that Xavi Hernandez was including for the candidate of Bayern Munich next manager because Bayern Munich currently was linked to several names such as Xabi Alonso, Mourinho, Klopp, or even Ole Gunnar Solskjaer and currently Xabi Alonso is the closest candidate to be the next manager of Bayern Munich
Recently Leverkusen owner has giving the statement about this rumour and they will let Xabi Alonso to leave Leverkusen which mean although Xabi can bringing Leverkusen to being an the champion of Bundesliga but he will still leave this team after this season ended but Xabi hasn't decide yet whether he will choose Bayern Munich or Xabi will return to Premier league as Liverpool manager
About Xavi Hernandez recently Barcelona sport director Deco has give his reaction to Xavi future because although after Xavi has decide to withdraw from Barcelona but Deco said Barcelona have no plan to look for new manager immediately because he said it is too early for Barcelona to find new manager because the competitions still not ended yet but Barcelona still hope Xavi want to change his mind and still train Barcelona for next season this because Deco still not sure if Xavi leave then Barcelona will be able to performing well under new manager