Valve is taking a cautious approach to games using AI-generated artwork, and has been rejecting at least some games that use it on the grounds they are using artwork which may infringe on copyrighted material.
The Vergecast
Steam Is Apparently Rejecting Games Using AI Generated Assets
Valve Says No to AI Art In Steam Games
Steam Is Apparently Rejecting Games Using AI Generated Assets
Valve Bans Games From Using Copyright-Infringing AI Art
Steam (service) - Wikipedia
Valve won't approve Steam games that use copyright-infringing AI artwork - The Verge
Steam is cracking down on illegal AI usage
Valve Is Not Discouraging the Use of AI, but Will Reject Games That Use Copyright-Infringing AI Assets: Report
Developer claims Steam is rejecting games with AI-generated artwork
The AI Breakdown: Daily Artificial Intelligence News and Discussions
Valve responds to claims it has banned AI-generated games from Steam