Disney would never make a statement about it because their statement would be “we’re waiting until we get the rights to Empire, Jedi, and the prequels in 2020 before we do any new release whatsoever that isn’t a repackagaging of the 2011 discs.”
It would be insanely awkward for them to say that, which is why they’ll simply say nothing until they actually are working on something.
After reading the responses to my comment about a I-IX boxset, I think it’s more likely they release the films individually and, at the very least, make each OT movie its own two-disc set. For one thing, the profits from sales of ANH would go straight to Fox and they wouldn’t need to worry about auditing Disney to make sure they’re getting their full amount from sales of a big I-VI or I-IX set.
Of course, I’d love to see the '97 versions included as well, and the theatrical prequels (and the imax cut of AOTC).
I haven’t even brought up the likely possibility that this will be the debut of I-VI on the new 4K UHD format. Now that Disney finally jumped on that Bandwagon last month (Fox was actually the very first studio to announce titles almost two years ago) they might get TFA and RO out on 4k before the holidays and then we’ll see TLJ hit the format in April.
With Indy 5 hitting theaters in July of 2020, I wonder how Paramount will handle the rollout of the first four on UHD. The 2012 blu-ray transfers of Temple and Crusade used the 2008 masters (which showed up as the WoWoW broadcasts around that time), but those were only finished at 2k unless I’m mistaken. Maybe they’ll redo those scans to take advantage of the extra resolution. Raiders was redone yet again with a 6k scan and 4k finish. Crystal Skull was finished at 2k (at least according to imdb), which is too bad but it makes sense considering all the cgi, none of which would’ve been rendered above that resolution.
Close Encounters hits 4k this month, with all three versions on the same disc using seamless branching just like the 2007 release. The OT movies have so many differences once you hit '97 that it would be impossible to branch them onto the same disc, although it might be possible to do that for the '97/'04/'11 versions.