I agree with you, I think Xabi needs one more year with Bayer Leverkusen to get a more respectable position. However, according to media reports, Bayern Munich are interested in signing him. Bayern Munich will part ways with Thomas Tuchel at the end of the season. They need a technical director and I'm sure they will also want to weaken their opponents as they always do. If they insist on Xabi Alonso they can finish this transfer, there are very few who can say no to them.
Bayern Munich are coming to recruit the only promising manager in Bundesliga this season, the Bavarians will do everything within their reach to ensure they're all in for the top target. Leverkusen will continue to fight to get tight grab on Xabi Alonso because he's the frontrunner for the club, the formidable pillar behind the sudden improvements of Leverkusen this season, it's not always easy to keep striving for good results. Xabi Alonso will never stop believing how far he has gone this season, accomplishing and breaking records this season, they've been doing the ultimate moves.
I think all clubs will be interested in recruiting Xabi and appointing him as their head coach, not just Bayern or Liverpool. Whether he survives or not, Xabi is now a highly respected manager, especially if he is able to win the Europa League, Bundesliga and DFB Pokal trophies all in one season. Leverkusen will receive many offers in the upcoming transfer window, not only offers for Xabi, but also for their key players.
Bayern will certainly try to recruit Xabi, this is part of their strategy to dominate the Bundesliga again, where I believe Leverkusen performance will weaken if Xabi leaves next season. However, it is not impossible that Xabi will survive, and they will fight again to create an unbeaten record, so that competition in the Bundesliga will be even more competitive.
On the other hand, if Leverkusen is able to achieve treble winners, then a number of bonuses they get can be used to increase the depth of the squad, so that they will be able to compete in higher competitions, namely the Champions League. Let's wait and see how many trophies they can win this season, and how the speculation about Xabi future ends.