That's a tough question. The Court really hasn't taken up many Second Amendment cases and they seem to want to avoid them. I've always thought this was one of the more common sense gun safety proposals that would be presumed constitutional, but this is a very conservative Court. I've always read the prefatory clause as a limitation on the operative clause. I think one must read the entire amendment to understand the purpose and meaning. The so-called originalists have really perverted the meaning and intent of the 2nd Amendment. Altogether though, there really isn't a significant amount of 2nd Amendment jurisprudence to really draw from.
Let's wait for an en banc review from the 9th Circuit first before we discuss whether or not this might go to SCOTUS.
That's true and actually quite likely really.