It is an STF that is not in the Fleet Action queue (Don't know why not), but it is a replayable 5 user mission and you should be able to pick it up from one of your contacts under Hail Starfleet (Badge icon) next to your mini map.
I honestly don't know how it's still considered an STF. It's not in the queue, it's untouched by any of the STF changes. There is no special reward for it like the Borg pieces or Maco gear, and in general the rears for it was always disappointing. I think they should either revamp this into an actual end game STF or just Nerf it into being a casual mission.