First, Teams works well on Linux. I have been a desktop Linux user since the 90’s and I use Teams every day (week days at least).

Second, that does not mean they use Teams as their preferred collaboration software.

Even on Windows, you use what the meeting organizer used to schedule the meeting. And if you interact with external companies, you are going to be joining Teams meetings regardless of your preferences.

And, if you had to make a reference you thought everybody would get, Teams or Zoom seem like your best bet.

So making reference to something someone one would say in Teams is not exactly Ronald McDonald admitting he eats at Wendy’s.

If Teams IS their preferred solution, I think the bigger deal may be a European company relying on a US cloud provider, even more than proprietary vs FOSS. At least, that is my view.

I would love a great Open Source video conferencing option to emerge and become popular though. As above, this kind of software has network effects and I would rather get invited to Open Source meetings if possible.