Yes, it happened.
How does it work? Basically like this: You have a case in federal trial court (also called District Court). One side or the other loses on a point that it thinks is critical. That side appeals the decision to the federal appeals court (Circuit Court). The Circuit Court decides the appeal. If the loser is not satisfied with the Circuit Court decision, it files a "petition for certiorari" with the Supreme Court. This petition is a request to the Supreme Court to hear their appeal of the Circuit Court decision. The Supreme Court justices get together weekly to discuss all the petitions for certiorari that they haven't yet made a decision on. Each petition may be "granted", which means the Supreme Court will hear the case. Or the petition may be "denied," which means the Supreme Court won't hear the case and the Circuit Court's decision stands. It could also be "returned for further discussion," which means they haven't decided either way. On occasion, the justices may ask for additional information from one or both parties, information they think they need to make a decision.
The Supreme Court typically discusses pending petitions on Fridays and the resulting decisions are announced the next Monday.
The announcements yesterday specifically said that the Court has granted certiorari on this case,
New York Rifle & Pistol Association v. Corlett: