Found it!

And wow, first time lore drags me in this hard. I've been out of game for a while and missed the whole drifter part, but this stuff is facinating :D

Maybe the Sleepers found a cure for the Jovian Disease or are very close to it?

So on the wiki I found out about the Sleeper-Jovian connection. Especially the part "Finding a Cure" is interesting.

Considering the might of the Jovian Empires and their inability to find a cure for the Jovian Disease, it is no wonder why the Sleepers erected such a massive research network in w-space for the same task. It is difficult to know if the Talocans still existed as a society when the Sleepers showed up, but it is certain that if they did the Sleepers eventually destroyed the Talocan civilization in the attempt to fix their own corrupted DNA. While some Talocan settlements were turned into quarantine zones, where the Sleepers could attempt to reconstruct the circumstances that lead to the Jovian Disease, other sites were used for processing and storing the vast amount of the data the research provided.[21] As example, Sleeper databanks were placed near Talocan settlements for monitoring and storage purposes.

So they wipe out a civilisation in search for a cure, why not do it again? They allready started monitoring us again..

It is also interesting that the Sleeper drones do not appear to take notice of capsuleers entering w-space, erecting starbase towers near the moons or places small colonies on the planets. Only when the Sleeper or Talocan assets are being directly threatened do the drones take action. This shows what the Sleepers found important and that their interest stop outside of safeguarding their own research. There is no indication, or reason if this hypothesis is true, that the Sleepers should have any interest in returning to New Eden, even less invade, before a cure has been discovered.

So maybe they did found a (partial) cure ..