Is Microsoft Teams down?

Nope

As of 21:51:47 UTC on 2022-01-23, according to Microsoft nothing is going on, it's all good for now.



The last update was six days ago:

2022-01-16 23:01:46: "We're investigating an issue in which users may be unable to access their Exchange Online mailboxes and calendars. Further details can be found in the admin center under EX315207."