Didn't they just throw a (very public) fit over Perplexity doing the exact same thing?

The most egregious thing Perplexity did was to straight up ignore robots.txt. Cloudflare promise not to do that, so if we take their word for it, it's a quite different setup.

That said, I'm not fan of letting users forge whatever user agents they please. Instead, AIUI to opt-out of getting crawled I have to look for the existence of certain request headers[1].

[1]: https://developers.cloudflare.com/browser-rendering/referenc...