A lot of staple combos probably would be preserved in lower hitstun if everybody just reached the apex of their jumps those few frames earlier that would be lost from a lower hitstun constant. A key example of something being lost but easily retained through hitting their peak jump height earlier would be DK's Cargo Toss > Uair. Staple Bum combo right there, and a key example of something that works with the hitstun right now, but any lower it would be lost. If DK reaches his max height a few frames earlier, tada!
My guess is that most combos would be preserved in such a matter, and we have every ability to keep them regardless. IASA or simply less endlag on the select moves would then be done if simply faster jump speeds (read, NOT fall speeds :V) alone do not preserve those bread and butter combos certain characters cannot afford to loose.
Once the next Nightly is released I would love to see a test set for these kind of changes. Kupo has done one thing right (I'm not saying its the only thing, its just the one thing I'm pointing out ._.) and that is get all of us focused on the game's physics. These arguments now are crucial, and for all we know characters will magically fall into place once they are set. One can dream...
