- I imagine them finding a lot of Force-draining Rakata technology on a stop off once they arrive in unknown space, which they would later discover were weapons that the Rakata were developing to use against the peoples of the known galaxy because of course, they're power hungry, unstable buggers that would like to squash everyone under their boots ;) Whether they find these things before or after finding Revan and Meetra is totally up for discussion. Either way I'm sure the older two would be able to offer some insight on the topic. I don't know how far into the 'newer' SWTOR content you ever got, but something along the lines of the Eternal Fleet perhaps, but instead of ships they'd essentially be new and improved versions of the Star Forge and in en masse style numbers? 

- following from that, I was thinking to myself the other day that if Revan and Meetra were alive this whole time and watching the chaos unfold in the known galaxy, they would have to be very very preoccupied with something just as important to stop them from packing up for a few years to return to save the day? So what if, Meetra and Revan have been chasing the creators of these super weapons around unknown space (in the Ebon Hawk too, perhaps? :3) and trying to stop them from returning to known space, destroying as many of the weapons as they can. (but of course, this is the Rakata...and I imagine that as many as they destroy, the more they make? Hahaha)

- Further inspired by Knights of the Fallen Empire/Eternal Throne, there's the possibility for Valkorion/Vitiate to have somehow been involved in the whole matter? Perhaps he awoke the first Rakata from cryosleep and struck a deal with them, and so forth... So that after Voldon killed his body at the end of the Knight Storyline (?) his spirit remained alive and was pulled back into unknown space where he remained, plotting to overthrow everyone and so forth, remaining sustained by the Force-draining tech, which would suck the life out of any planet, being etc that they send it at, and then pour that life energy into Valkorion and the Rakata masterminds instead to keep them alive. 
Naturally, they would have to destroy all of the objects to be able to be rid of them, as an ultimate end goal? :D

- Further reason for Revan to want to remain there, if he desperately wanted to help Renso and the True Sith stop Valkorion he wouldnt want to give it up that easily. (But Y'know, with less of the ridiculous bat shit crazy Shadow of Revan version of him because that was just totally ridiculous XD)

Thaaaats what I got so far! Obviously we can add to it and flesh it out more haha XD