Gura is basically challenging the integrity of the court if they DON'T take this case.
He points out the lower courts' defiance on the issue. They have indeed limited Heller to the facts of that case only, and say that unless there's an exactly same law passed, then the lower courts can't rule on it because SCOTUS hasn't. By that logic, SCOTUS can't review any 2A case because all the lower courts agree that SCOTUS hasn't ruled on it-circular logic. Thankfully Moore didn't follow that. Hopefully they take the case. If not, Gura aptly points out lower courts will just continue to sit on their hands.