Auth with MS accounts is a giant mess. When I was a city councillor I had a corporate O365 account from the council (used for council email and virtual meetings over teams) and simply trying to sign out of the thing or switch to another account was always fraught (I've got a personal account that's basically just to associate my windows license with and a work account used for azure access). You'd often end up in a state where teams would just refuse to sign in and you'd need to reinstall it to get it to work again.
Trying to be actively signed out is also a mess. You can use the teams app to join teams meetings others have setup and invited you too without teams access yourself. Though of course if you have an MS account teams can see it ends up trying to use it and then saying you don't get teams access via that account and trying to sign out and join the meeting with an account associated with it often just doesn't work. A colleague actually ended up requesting he got an o365 account with teams associated with his corp email because of this issue as he had occasional meetings with external people over teams. We have a corp o365 setup for our ops/admin team that engineering normally doesn't touch but because he had a teams invite sent to his corp email he got dragged into it.
Trying to be actively signed out is also a mess. You can use the teams app to join teams meetings others have setup and invited you too without teams access yourself. Though of course if you have an MS account teams can see it ends up trying to use it and then saying you don't get teams access via that account and trying to sign out and join the meeting with an account associated with it often just doesn't work. A colleague actually ended up requesting he got an o365 account with teams associated with his corp email because of this issue as he had occasional meetings with external people over teams. We have a corp o365 setup for our ops/admin team that engineering normally doesn't touch but because he had a teams invite sent to his corp email he got dragged into it.