The SCOTUS will never approve a change to the Constitution as a result of an Executive order.
Nobody said SCOTUS would change the Constitution. There will be no wording added to the Amendment. However, an interpretation of the wording "under the jurisdiction of" will be defined. If/when an executive order is written and/or legislation is passed with regard to Birthright Citizenship, the court will determine the constitutionality of those statutes, not change the amendment.
Should be an interesting decision, whichever way it goes. If visitors no longer have the right to come here pregnant, in order to have their children born here, for the purpose of gaining American citizenship, a lot of money will be lost to businesses set up to provide that service.