Anything that looks underaged, bestiality, or extreme non-consent would be something Patreon would object over. Did they at least tell you from what date to date the pictures might be posted at, and thus narrow down the search?
EDIT: Oh you mean DeviantArt. Well I found a section in their TOS that might be relevant for you:
" DeviantArt is, unless otherwise stated, the owner of all copyright and data rights in the Service and its contents. Individuals who have posted works to DeviantArt are either the copyright owners of the component parts of that work or are posting the work under license from a copyright owner or his or her agent or otherwise as permitted by law. You may not reproduce, distribute, publicly display or perform, or prepare derivative works based on any of the Content including any such works without the express, written consent of DeviantArt or the appropriate owner of copyright in such works. DeviantArt does not claim ownership rights in your works or other materials posted by you to DeviantArt (Your Content). You agree not to distribute any part of the Service other than Your Content in any medium other than as permitted in these Terms of Service or by use of functions on the Service provided by us. You agree not to alter or modify any part of the Service unless expressly permitted to do so by us or by use of functions on the Service provided by us. "
In simple terms, some of your AI generated art might look too similar to another artist, whose work isn't AI generated, and they are claiming a copyright infringement. Though, I'd think that DA would tell you which images are a problem.
