For one, everyone should know that AI-generated text detectors have already been debunked by ML researchers. You can Google "AI detector + arXiv" for a list of papers. It's reasonable to specialize pitches with AI. Sales people do it. Everyone does it. What I would stay away from is pitching expert quotes or articles (i.e., something they would actually post) written by AI. Not only because of the ethics, but also because your expert is ... actually the expert. And you can avoid triples and em-dashes, which AI likes to over-use, and use shorter sentences. Personally, I've found going super-personal is pretty effective. I know a lot of more experienced folks like the formal email approach, but the open/engagement stats don't support it anymore.