The way things are going, both Barcelona and Bayern will be looking for managers too fairly soon.
Also, come the summer, there's going to be a lot of managers on the move after the Euros.
I'm not sure they'd move for Alonso even if he wins the Bundesliga. Bayern might, but if he wins the Bundesliga, why not stay and do it again? Leverkusen despite their spurs-status is a big club too. Could see Barcelona wanting him too, if they sack Xavi later on in the season. Low-key hope they stick with Xavi. But yeah, maybe Liverpool will go for the hype manager. Alonso does look like a solid manager thus far.
De Zerbi, maybe. One of the article on the Athletic mentioned that '[...] and though many people in the industry speak about Pep Guardiola leaving this summer with Roberto De Zerbi taking over [...]' If not, then Barca might be looking at him, Berrada might want him for United if we decide it's time for a change in the summer. Don't think he'll land at Liverpool either way.
Nagelsmann maybe, if Germany crashes out of the Euros early. Don't think Mourinho is a completely implausible choice for them. Don't think it'd work out.
Ancelotti would probably be among the better short-term option, and he loves England and the Premier League, but he just extented with Madrid and is doing great.
Zidane? Thought he was taking over France, but Deschamps extended. But he's being say no to every job, and The Athletic reported Juve & Marseille were the only other jobs he wanted.
Michel? Wouldn't totally surprise me, but surely he needs to do more before landing a job like Liverpool.
Simone Inzaghi? Have been going a brilliant job in both his manager jobs so far. Trophies with both Lazio and Inter, even got to the CL final. Doesn't really play in a similar style to Liverpool, I'm sure he could adapt a bit. They're in a title fight again this year. Inter have been performing more or less as well as Liverpool while he's been there, and Inter are skint compared to Liverpool.
Stevie G? For the nostalgia. Think it'd fail miserably, and therefor all for it.
Mourinho? He'll clearly manage anywhere in England. He's free, he's a well-known name. Even if Liverpool have a better structure than United, they have the same type of owners. Could see it happening, don't think he's their first choice. Don't think Mourinho would mind that he's been at United in the past. Liverpool might.