Rosetta 2 is fast and won’t get in your way. It’ll be part of the Apple silicon ecosystem for years to come. FWIW, my wife runs Teams all day for her teaching on an M1 Air and still gets incredible battery life and performance. No reason to avoid it in my book.
I get why you would think that, based on lots of past experience with ‘emulators’ (although technically this is a ‘translator’), but… I have been using Rosetta whenever needed and absolutely cannot tell the difference between an Intel app and an Apple Silicon app.
Now that MS Office is out with native support, I would assume Teams will be coming fairly shortly. Surely MS knows this is an app people want, and Slack has a beta, so they don’t want to be perceived as falling behind.