The idea that only supply packs allow long rests is intriguing. It should be thought over wether that would be a possible solution for the too-easy-too-much problem of long rests. I cannot grasp all ramifications of such a feature now. I try to avoid long rests as much as possible anyway.
Normal food could be used to restore hp then, but only out of combat. I find it a bit annoying that only short rests are useful for restoring hp, and I see it not as such a big win for tactics and management that you otherwise have to waste slots or slurp potions for out-of-combat hp.
Much depends on the number of loot in the release version of course. They could make long rests a terrible burden by reducing supply and foot already with the current system. As all the chars of my planed party except one are dependend on long rests, I'm curious what we'll get.