If it does go to the SCOTUS, then there's a much better chance of a pro-2nd ruling, compared to before.
It's a safe bet that Roberts, Alito, Scalia, Thomas, and Kennedy will vote in favor of upholding the appeals decision. Unless the remainder chooses to uphold the Constitution, Stevens, Breyer, Ginsburg, and Souter will most likely vote in favor of the ban.
There's a good chance they'll pass, just like they did with the Rock Island Armory machine gun ban case or any number of other 2AM cases. Or they could rule narrowly and sprinkle non-precedent dicta over their decision.
Constitutional depends on the wording of the document, the legal precedents and the general sense of the people. At one point a Black person was constitutionally not a human being, just 3/5 of one for purposes of the census. Now he is constitutionally considered one. At other times corporations were not a person under the constitution. Since 1873 they have become so. And so on.