Probably means fan, shills have undisclosed ties and I doubt he means Simon has undisclosed ties to the entire AI industry, that would be very impressive if so.

Merriam-Webster: noun, 1b: one who makes a sales pitch or serves as a promoter

You might want to ask the guy who said it first what he meant; I was just pointing out that your work isn't particularly Anthropic-biased, in my experience.