I have noticed..
Webex's call quality seems worse than normal but otherwise OK. Skype for business is crap too but then it was crap before COVID-19 so seems to be behaving as expected.
Not tried teams this week but Zoom seemed to be good for an office Web conference but crap on Sunday for my youngests' Chinese school lessons (they tried keeping it going but attendance dropped to 10% so they're going to move the whole school onto using Zoom until things settle down).
Which does lead to an interesting problem - what will happen if schools move over to web conferences? Not just the services themselves but pupils internet in general when millions of kids start videos on mass everyday?