Just try with your old games. They only increased the contrast of the game boards in the new editions, all components are identical in size and material used. At least the Gipf board was increased by 3 (6) cm in both directions. It’s now about 25*23 cm² folded vs. 22*20 cm², but it would still fit into an old box without the insert.
(image pending approval)
The boards (old and new) are about 10 mm thick, so 6 of them would indeed fit into a new box easily (given they’ll modify the Dvonn board of course). But that would leave only about 4*29*7 cm³ + 6*25*7 cm³ to store all other components. This might get pretty tight. Additionally weight would be an issue.