I don't get it.
The court made a decision on the census, the making of which is a constitutional imperative defined in law. Why would an EO make a difference? The law is what it is.
Roberts indicated a pathway to resolving the issue. Be honest about why you added it. Or back off. He's not going to allow the president to overrule him. He's engineered a paradox from which the administration cannot escape without admitting it lied, or by omitting the question.