Forget that we haven't seen Awakened King, Queen, and Jack. We haven't seen Awakened *Kaido*. Or even if any of the Tobiroppo can do it.
Greg is very close to Oda, he even can´t post theory on his own who are close to the orginal story, he show it first Oda and the editors and they decide if he gonna post it or not because of spoiler warning.
Greg saying "we haven´t seens Awakened King,Queen and Jack" literally hint a big fact that he probably knows that all Calamity having awakened. And look what he saying here: We haven´t seen"....
Seen, it could mean the Awakened form is indeed a new and strong form for Zoans, in that case Jack not only show his hybrid form but he also have his awakened form who could be similar like monster point chopper.
With the fact that Greg know manystuffs before we even see them and he beeing close to Oda, I could imagine these words as big hints.
In the fact that Inu and Neko already using sulong against Zoan Jack as their trumpcard, showing you that Jack could take the W in this battle. Let say Greg "hint" is right and Jack kinda get a new form(awakened) with make him twice stronger then his hybrid form, I could imagine the battle against the sulong like this:
Jack get beaten up in his mammoth form>he switch to hybrid and show new skills against both Sulong, he kinda match them>Sulong Inu and Neko using their final attack>Jack seems be down but he then use awakened Zoan who is also the first shown awakened zoan in the manga>Jack beat both Sulong Inu and Neko....
Also he even hint that the Tobi Roppo could use awakening, in that case my prediction who could have it:
WsW/Drake/Sasaki(probably if he face Jinbe later).
Overall seeing Greg saying something like this hype me kinda more for Jack and the other beast pirates, this could became very insane soon.