They spoke to other agencies that are primarily WP shops, and they're all seeing that market dry up.
The whole thing is a lot of popcorn and sadness, and it's pretty scary for the WP ecosystem (which had been relatively stable and reliable for decades). Suddenly every company is wondering if they're next in Matt's crosshairs, WPEngine customers don't know what to do, a bunch of Automattic employees quit, and the community itself is divided about who's in the right (if either of them) and it's been a whole WTF journey for everyone watching from the outside.
Just read some of the Wordpress stories from the last few weeks if you really want to see the play by play.