Re: ...the core functionality of Teams
So if your employer went Cloudy, you'll all be able to chat about how none of you can do any work.
My employer went mixed mode a while back, and our cloudy part has proven as reliable as our on-prem. The on-prem part worries my most as its in our offices which are in lockdown, and we quite rightly can't ask staff to go to the DC floor in these times. I'm trying to actively disallow it as it's not something I'd want my kids doing when they grow up, so I don't want your folks kids doing it now.
The cloudy part I can port to another geography with a small code change, should the need arise.
I'm not saying you need one or the other, you need both, but being able to dump my compute in a virus free zone , when one emerges, in order to protect people "going to work" in virus hot spots, seems fairly responsible.