I do not believe this will be limited to Valve. I expect more companies to start covering their backside by implementing similar rules to avoid copyright lawsu

I do not believe this will be limited to Valve. I expect more companies to start covering their backside by implementing similar rules to avoid copyright lawsuits. I can't say I would blame them either. I am not a lawyer but I think one of the risks is that LLM's do not show their work so proving where something came from is likely to end up in court after a lot of expensive discovery is performed.