Future State event, this doesn't come as a complete surprise.
The Authority was first introduced in 1999 under the last issue of an Authority-centric series came out around ten years ago, so it has been a while since fans have seen this team, though they have seen independent a few times since. Within New 52 and DC Rebirth, Midnighter, Apollo, and the Stormwatch team have made appearances, but now it looks like the Authority itself is coming back as a team - alongside one of DC's biggest heroes.
In a tweet from Steve Foxe that has since been deleted, a cover was revealed for a series titled Superman and the Authority. Written by Grant Morrison with art by Mikel Janin and Jordie Bellaire, O.M.A.C. (complete with mohawk), and Natasha Irons.
This would not be Grant Morrison's first time telling a story involving the Authority, but it might be the first one he fully completes. He was involved in beginning a run back in 2006, which quickly ran into problems and ultimately didn't see more than two issues released despite plans for more. The series was later completed with a new creative team and released as The Authority: The Lost Year. Now, Morrison might have a second chance, which will hopefully go better than his previous attempt. He definitely has experience with Superman, considering he wrote the All-Star Superman. However, this does seem like a very unorthodox hero pairing, particularly since in its history as a series, The Authority has been known to be violent and even controversial in some runs. Superman is DC's poster child for goodness and the pursuit of peace, which makes him an unlikely candidate to partner alongside this team—especially considering how badly he beat up stand-ins from the team in "What's So Funny About Truth, Justice, and the American Way?" from Action Comics #775.
As previously mentioned, the cover also features Natasha Irons, Enchantress, and Manchester Black. Natasha Irons, the niece of John Henry Irons (aka Steel), is pictured with her hammer. She's been part of the Teen Titans and has been known to help out the Superman family; Natasha will likely be assisting Superman. Manchester Black and Enchantress's roles are not known, though Manchester could be ing up with the Authority or operating with his usual team, the Elite. Enchantress is usually a villain and has been seen on the Suicide Squad. Whether or not she will be helpful to Superman's team or be a main villain is unknown, as is everything else about this series since it has not been officially announced by DC Comics. Regardless, Superman and the Authority is an unlikely team-up that is bound to have some major head-butting between heroes.