Anybody that got hit in production by this did it to themselves because they have no working testing and release processes.
Even with a working testing and release process, this costs time (and therefore money) to fix -- testers don't work for free.
As mentioned in TFA, in addition to DMCA violations, Activision's claim will include intentional interference with contractual relations:
[P]laintiff must prove four elements: (1) that a valid contract existed, (2) that defendant had knowledge of the contract, (3) that defendant acted intentionally and improperly, and (4) that plaintiff was injured by the defendantâ(TM)s actions.
Most of these elements are trivial to prove. The only open question AFAICT is whether EngineOwning acted 'improperly'. I think EngineOwning will have a tough time defending themselves, but this suit surely can't be a surprise.
In computing, the mean time to failure keeps getting shorter.