I'm all for dogfooding, the only meaningful difference between slack and Teams to me, is the search for actual information that I know I've encountered in the past (it's easier on slack IMO), and the awesome way to interact/thread with conversations in a natural way.

Video-conferencing wise, I always have more problems with slack than with zoom/teams.

this already happened to some extent. the “blessed” way to develop github is in vscode (from ms), using codespaces (from ms), running on azure (from ms). vim/emacs users can use the terminal (although the codespace and port forwarding, at first, had to be done via vscode exclusively) but your entire toolstack needs to be installed each time you launch a new one.

collaborating with anyone at ms already meant you were using teams to some extent.

(former github developer)

This way they also don't send all their internal company communications to a third party, which would be extra stupid when you have your own in-house conferencing software to use instead.

I mean... it's a pretty hard sell to say "Hey boss person, can we use our competitor's software to discuss company business?"

My team also used Slack when I joined and were eventually required to move to Teams. We aren't forbidden from using Slack, I'm in multiple Slacks collaborating with various OSS projects and foundations every day.

Slack's video conferencing is archaic compared to something like zoom (maybe not teams), but out of all of the video conferencing tools, slack is the worst.

Slack video conferencing was absolutely awful and one of the main reasons we switched to Teams a couple of years back.

Is it better now?

There seem to be plenty of commenters combining Slack and Zoom so seems not. That's a redundancy right there that Teams solves.

I suspect they’re not replacing Slack’s video capabilities with this move. They are replacing Zoom’s.

Not sure, I dont work at Microsoft, but if my company did 70% of what slack does, sometimes significantly better (IAM). I would too, want my employees to use my software, and with that raise problems and make it better.

I understand the frustration of some people, but this is by no means something oppresive at all. A lot of companies use "X" office suite, and use zoom for calls , etc. It's okay for everything to not be centralized, always.