Not only do new Quorans not find out about Quora policies when they join; old Quorans don’t find out about Quora policy changes. Several Quora users a couple of months ago complained about a Quora insider (Bodnick I think) using an infographic in an answer. Quora policy used to be that you could not use a third party infographic, and insistence on doing so got Xu Beixi a six month edit block.
Why no, infographics are not mentioned in the current policy. That aspect of the policy got quietly rescinded a few months ago, in time for Bodnick not to be in violation.
Quora using the question and answer format to publish its own policies was criticised at the start of Quora, and the criticism is right. With no use of blogs or even answer wikis to publish policy, users have no easy way to stay up to date.