They've had this feature for sometime and it is pretty cool. :)

About a year ago there was an ask HN about conference room systems. I had just recently gone through the process of selecting and went with zoom. The "airplay" feature was one of the reasons why.

Here are my notes: https://news.ycombinator.com/item?id=19455428

Edit to add one note: They recently (last six months or so) added a feature to allow you to share multiple screens at once. We've setup most of our conference rooms with two screens so it's really cool when two people in a room can wirelessly share their screens and you're able to see both at once.