Not being able to apply for copyright doesn't prevent you from getting charged for infringement.
"I made it with AI, it's not copyrightable" is the 2023 version of uploading a show to Youtube and adding in the details "I do not claim Copyright on this material. All Copyrights belong to their respective holders". It's still illegal even if you don't claim to own it.
Email solicitations to potential buyers, so seems likely.