It has been my impression that the Brokers will step up and collectively be the gatekeepers the SEC insists they be.
We're seeing TDA and a few other Brokers forbidding opening positions and only allowing liquidating orders for companies not compliant with Amended Rule 15c2-11, whether the stocks trade on the Grey Market or the Expert Market. Once they're all onside with no buy orders/liquidation only the Expert Market will hopefully go the way of the DODO bird.
Cross yer fingers, throw salt over your shoulder, 3 coins in a fountain, whatever works.