Do not disturb
The yang to the yin of meetings is the do not disturb status. In Lync and S4B it stopped people talking to you. As far as I can tell in Teams, it's just yet another status colour and doesn't actually do anything, so you can still get sucked into meetings anyway and have people suddenly jabber inane questions at you with no preparation because you're somehow regarded as the domain expert (i.e. you might have looked at it once). Yeah, thanks for badgering me on Teams, I was in danger of getting something properly finished.