I think VII's release is too early, but time will tell. To get them out then Disney would have to think it can earn more selling then new editions than it'd have to pay to get the rights back early. My bet would be on something happening in 2020, either Fox selling Star Wars's rights for three boatloads to Disney or the two companies working out some split for the trilogy.

And of course there's the question of whether people will sill be buying movies at all in 2020. I don't truly expect everything to go streaming/subscription, but I think the big goldmine for home video sales peaked about when the first set of DVDs came out.

The other test will be whether whatever gets released passes fan muster. You can go ahead start writing the "here's what the new OT versions get wrong" articles now. There will be too much DNR or the colors will be wrong or the sound mix will be off or something. Disney (or Fox or whoever) would be smart to involve the fan community in the process somehow.