This sets a terrible precedent. We’ve already seen some pretty not-awesome shit from Valve in regards to their other lootbox farm.
Specifically, TF2 is a bot-infested mess, and for years now, their only real involvement with the game has been to try and squash fan projects. This was first seen with TF2C and Open Fortress, where they asked the devs to take down all downloads and promised full official releases before ghosting them, and now with TFS2, where they just went straight to the DMCA.