They left open the possibility of taking the issues up later, after another conservative is appointed to the SC.
Correct, there will be another day on this in the future.
The SC cannot give an advisory opinion so they'll need a proper dispute to get involved.
While nothing is certain, I'm not too concerned with this. In 2010 the SC incorporated the 2nd Amendment in McDonald v. Chicago.
It will take a bigger twisting of the constitution than Roberts pulled on obamacare to get around McDonald.
It just takes time...and a few more appointments like Gorsuch wouldn't hurt either.
I am hoping that is what their thinking was.