Not that I'd have any reason to use it but perhaps it's a pathway for Microsoft to eventually introduce Office for Linux. They're also competing in the same space with Slack which was already available for Linux.
QuoteMicrosoft is bringing its first Office app to Linux today. The software maker is releasing Microsoft Teams into a public preview, with the app available in native Linux packages (https://aka.ms/get-teams-linux) in .deb and .rpm formats. “The Microsoft Teams client is the first Office app that is coming to Linux desktops, and will support all of Teams’ core capabilities,†explains Marissa Salazar (https://techcommunity.microsoft.com/t5/Microsoft-Teams-Blog/Microsoft-Teams-is-now-available-on-Linux/ba-p/1056267), a product marketing manager at Microsoft.
https://www.theverge.com/2019/12/10/21004846/microsoft-office-linux-microsoft-teams-app-launch-public-preview (https://www.theverge.com/2019/12/10/21004846/microsoft-office-linux-microsoft-teams-app-launch-public-preview)
Somewhat encouraging. It would have been great in my work to have had MS Word, Excel and Powerpoint in native Linux format, but by the time such is available I'll no longer need them. Plus, LibreOffice and Softmaker Office are getting more compatible with each update.