It is also a fork of an extension that contained malware, so an automated code review tool trained on malware might be catching it.

That's a possibility, too, but the email specifically mentioned pornographic content or extensions that might "drive traffic" to pornographic sites so that seemed like the more likely reason.

I was actually gonna ask, isn't hoverzoom a malware? But I guess this is a fork of it. I've since switched to Imagus but I do miss HoverZoom.