Surely, I'm not the one here, but it's interesting to try and see if we could guess this time. We've had a lot of hints already.
1. Velen is repairing Exodar in order to go and kick KJ's ass.
2. Illidan told Akama to prepare a detailed plan on the assault of Argus. We got Akama and Illidan's task to obtain the Keystone that would allow us to open portal to Argus.
3. We were directly told that INSTEAD of Tal'dranath we'll get something really more interesting than (another ancient elven city like Suramar).
So, all things considered. A guess of mine is - Argus, a location of it will be an Isle-of-Thunder\Tanaan Jungle type new landmass with a raid in it. So, in a huge event\quest chain at 7.2 we prepare Exodar, take the Keystone and open a portat to Argus. It's obvious that Legion's main base is too heavily protected so we can't just crash on it and go straight to KJ's throne room. So, we land somewhere nearby, and through events\scenarios\dungeons we must: 1) clear the place
2) hold the base from the Legion.
3) establish a base, make stable portals so we could get through an army big enough to make an assault of the main base of the Legion.
4) make an assault BEFORE all the might of the ENTIRE Legion will be there.
Then, maybe with a couple of 5-mans, there will come a raid on Kil'Jaeden and his minions (Mephistoth for example).
What about more small raids like Trial of Valor...dunno, maybe Sylvanas will make a move in 7.3 to attack Alliance while its main forces are on Argus. Maybe not. Maybe, as some want, Jaina will do something bad.
So, when we Kill Jaeden for good, we will likely return only to find out that in our abscense almost all our positions were lost. Maybe the demons in Stormwind\Undercity seen in Kilrogg encounter vision will occur.
And then we'll be up to the Tomb of Sargeras raid in 7.4 with Sargeras as the final boss of expansion.
Does that seem likely?