I know it's old but it's not what I understood from the article
"Wrestling:
Wrestling is acceptable only if knockout moves are not deployed. Facesitting and seemingly non gentle scissoring are not acceptable."
What is forbiden here are smother moves, but as far as I understand there is not ban on grappling/submission wrestling because there is a clear safe word (aka verbally submitting or tapping out), it is something that is between consenting adults and it is not life endengering pt overly degrading (it"s basically like any other martial arts, except competitors add more sexiness and theatric to it)