Using Microsoft Teams on macOS, including installation, features, and compatibility
Microsoft only has to update Electron to support Apple Silicon like the M1 which is fairly easy to do. Electron 11 (which supports it) has been released on October 2020 already and we're now already at Electron 14.
Thing is, I don't think they will. They are moving away from electron and going for Edge Webview2. Problem is, the closest we have to a release date for Mac support is post 2021.
So don't hold your breath: this will take a while. Meanwhile, using a browser isn't a bad solution. Chromium based browsers like the new Edge or Google Chrome are fully supported now (screen sharing having been implemented recently).