I don't see any reason why Kimmich could leave Bayern, he just said that he doesn't want to wait until the summer to start discussing the terms of a new contract, he wants to sit down at the negotiating table now to understand what he can expect in Bayern. I think that these are just assumptions that he could move to Barcelona or City, because Bayern is also interested in keeping such a player in their team, although first Kimmich needs to see the terms of a new contract.
These days many people are looking at older players to go towards Saudi league because that seems like a great way to make more money than you made your entire life. Kimmich is getting paid 20 million, which should drop to be fair because he isn't a 20 million a year kind of guy anymore, but lets assume that stays, he wasn't always making that much, he probably made less than 200 million all his life, he can sign a 2 year deal with some Saudi team that could see him make 200 million in two or three years.
But in this case, most people think he is going to be either staying at Bayern (most likely possibility), or go to City or Barcelona. City came out as a big possibility because Kimmich could close the gap that Rodri left behind, and Kimmich would be great there without a doubt. However, the issue is that, City shouldn't really get a player for 20 million a year, or even get anyone as great as Kimmich, when they know Rodri will be back next season, what are they going to do with both of them at the squad at the same time? Will have to bench one of them, that's too much for a bench player.
Hmmm, all those points are true.
But to be honest if we looked up towards the end. We can clearly monitor it that Barcelona coache are just trying to figure out the club for Kimmich's signing. I mean he wants Kimmich to move to Barcelona. Because he already knew it that how to use Kimmich in the heart of the team sheet. Barcelona also has a serious shortage of defensive midfielders. Since Busquet's departure, Barcelona's defensive midfielder role has not been fully fulfilled. So for that reason, I think Barcelona could do the most to sign Kimmich.
In addition, let's also say that Kimmich's move to Manchester City is almost impossible. because Kimmich is act as crucial role player and Manchester City has Rodri although now he is injured but he will play in his X11 sheet as soon as he recovers from the injury. Despit Kimmich being the starting line up player, he will not prefer the substitute.
So it's meant to say that people who say that Kimmich will go to Man City are not the case, he will prefer Barcelona as compared to other clubs. Because his role is empty in Barcelona, and Hansi Flick also likes him.