Awesome! Thanks for the heads up Nathan.
Confirming this did the trick!
You have to also copy/paste the urls generated for published posts into the corresponding feilds in Settings/Legal as if these were ‘externally hosted’ Terms of Service & Privacy Policy pages, if you want the links to these in the new signup dialog to work. (not sure why FAQ is omitted from sign up dialog, but you can also set this url here as well - though not sure purpose of this feild/what otherwise links to it if not included in signup dialog?
A workaround that might unravel if the site ever moved to another url, but great in the meantime to at least allow people the option to see what the terms of service etc actually are before they sign up!