Yup, one major issue. We can't log out properly!! Before, as long as you hit 'Sign out', you were prompted for your password when logging back in. Now, it just logs you in automatically! And yes, we checked the Windows Setting for Accounts>Access work or school - empty!. There's no setting that asked us to 'sign in to this app only' or I can't find anything out of the ordinary in the settings or registry editor, which is very concerning. I hope this gets fixed by the drop dead date, but for now, we cannot use New Teams the way it is right now.

https://learn.microsoft.com/en-us/microsoftteams/new-teams-known-issues