@met They used to have an official flatpak, but few months back they sent an email and announced that they are removing it. The current Flatpak is done by a guy as a personal project:
My issue with this Flatpak is that for an app that needs access to lots of things on my computer, I'm a bit hesitant to install third-party Flatpak. This is because I cannot use Flatseal to disable permissions and still have a function Teams.