Good. Until a studio can point to a known-dataset that isn't just ripping art illegally from sources they don't have the rights to use then it's just not worth the risk.
It's not 100% unrealistic that large studios like Blizzard and Riot (who have very clear styles that "work well" with AI generation weirdness) will eventually have huge in-house datasets that they own since it's all created under the umbrella of their employees and contractors who already sign away all the rights when they make content for the games they're working on. But until that happens, it's so obviously a red flag / great area that Valve's move is just a no-brainer.