Personally, I've always felt like RoF should be way more like Classic: Infinite blocks (so also, infinite inventory). I feel like RoF's system of not having infinite blocks or items makes it almost impossible to build nice, big houses, and be creative. Because of this, you'll often see cobblestone houses or other quick 3x3x3, and in my opinion RoF gets boring after awhile because of this. However, the head staff made it very clear that they wanted RoF to be about surviving, and not make this a little more challenging Buildbox.
For this reason, I'd say people should definitely not be able to get their items back, even if they can "buy" them with cookies. In fact, I feel like most items in your inventory aren't worth your cookies- You can get them all back. Maybe from the shop, maybe from the maps. And if you somehow manage to die with an amazing, enchanted weapon or 10 supercookies, well, should've been more careful. It's not a very fun thing, but shit happens. RoF is about surviving, and giving people the ability to get their items back removes the danger of dying. In this case, people won't be scared of dying anymore (so the game isn't really about survival anymore) but they still won't be able to build big and nice-looking houses (so the game isn't about being creative either).
tl;dr RoF is about survival, adding this takes the challenge away.