That part is describing Google SEO spam. I don't know how it works but it clearly does work if you've used Google lately.

I was unclear how Google's bot would index it if it was behind a paywall. But the "Host two crap tons of content", with the non-paywalled site pointing to the other, would get around it, allowing the hypothetical big spending AI crawlers to find it.

Yep, exactly this!

Host two crap tons of content across a wide swath of topics... one which points to the other?

I'm basically of the impression that this is already happening based on all the LLM generated slop search results I get - presumably for ad revenue (or in the case of Musk to push political views).

Yep, which is what i believe one manifestation of SEO spam - a bunch of crap that points to each other, further reenforcing its "authority"/"validity" in the eyes of a conventional search engine, and now agentic crawlers, etc.

Yeah, that could work.