More precisely, Xabi Alonso is currently being targeted by many of Europe's top teams because of Xabi Alonso's success in creating or building the Leverkusen team as it is today. I think it is quite worthy because Xabi Alonso has shown his qualities so it's only natural that many top teams want him.
I think the rumors for Bayern are still quite far away because so far Tauchel has been successful and has made Bayern Munich's performance quite strong, but we don't know at the end of the season what could happen if Tauchel has failed to meet the expectations or targets that have been set by Bayern management.
If Xabi can win either Bundesliga or Europa League, it's better for Manchester United to hire him and kick the bald guy. Manchester United already lose their legacy as one of toughest team in Premier League. They need to find a good coach who can able to develop the whole team, just like Xabi who wasn't sign many players, but he develop the existing players with a new strategy.
Are you sure Manchester United will sack Erik Ten Hag that easily? the article seems like Manchester United prefers this one coach even though his performance is not so good to apply the strategy in the game. Is that because Erik Ten Hag is a coach who does not disobey or in other words he always agrees with what management says? or maybe this is just my wild thoughts? I don't know.
Xabi is doing well at Leverkusen so it's natural that he's being targeted by many big teams in Europe. His ability to bring Leverkusen into the game we see today is remarkable. He started from the bottom and it wasn't easy.