While coordinating a fleet, myself and other capsuleers present also observed that there is no wormhole or anomoly in the gatelike structure when we entered the site. It could be a wormhole or something else and it may or may not be connected to the Hyperspace Network that the Drifters use. I’ll leave it to the scientists to determine what it is.
Our observations are slightly different regarding the appearance of the wormhole/anomoly and the arrival of the Dreadnought class ship. We noticed that the wormhole/anomoly appeared first and shortly after that, the Dreadnought class ship and supporting sleeper ships appeared.
Upon the destruction of the Dreadnought class ship, the wormhole/anomoly disappeared instantly and any remaining sleeper ships warped off. This strongly reminds me of the early days of the Sansha Incursions and what happend upon the destruction of a Revenant. Though I doubt that in the case of the Drifters the Dreadnought class ship is needed to sustain the wormhole/anomoly. It seems more likely that the Drifters considered the battle lost upon it’s destruction and didn’t want to waste any more forces.