From how I read it, the author seems to be suggesting that this list of IPs be on an allowlist as they see Google as "less nefarious". As such, sure, allowing google IPs is as easy as allowing all IPs, but discerning who are "nefarious actors" is probably harder.

A more tounge-in-cheek point: all scripts take an LLM ~10 seconds to write, doesn't mean it's right though.