Yes, and more to the point, they cut off Facebook and Google for distributing unreviewed apps to the general public. So the violation was using the enterprise key to evade app review by Apple. Which Apple does to protect its customers. And so Apple is just protecting its customers.
I believe Apple will do everything they can to keep them from abusing the ToS, but I also believe Facebook will try to work around any and every restriction applied to them.
Yeah, well, but Apple can always reject apps that violate their ToS, or revoke keys used to work around that. So ultimately Facebook can't win.
Except if they force Apple to nuke all of their apps, which would put Apple in a difficult position. But perhaps Apple could sandbox apps, and prevent them from doing stuff that violates ToS.