I read a rather thorough discussion of this case on another forum.
Several lawyers (including some major 2A attorneys) agreed that SCOTUS really had no option other than to deny cert, and see it playing out as follows:
The plaintiff(s) in this particular case in CT were arguing Remington violated the "Marketing exemption" language of the act protecting manufacturers from misuse liability. Since no verdict has been handed down as of yet in CT, there's nothing for SCOTUS to review. (Remington filed a motion to dismiss, which was denied by the CT Supreme Court. Case has not yet started in CT.)
The plaintiffs are arguing that the ads run by Remington/Bushmaster caused the SH shooter to seek out and purchase the weapon used and that the marketing materials stated the product was ideal for unlawful purposes. The 2A lawyers' consensus is that this case has a high likelihood of getting tossed once the Plaintiffs begin making their "case" in court, as the shooter in question was not the buyer (he killed his mother and 'stole' the firearm.) thus making marketing irrelevant (poof, there goes the case.) and Remington/Bushmaster regains the product liability protections of the Act in question.
If by some chance, things go sideways in the CT court, and a verdict is obtained for the Plaintiffs, Remington will appeal to SCOTUS, at which point, they'll grant cert and overturn the CT court's decision.