I think the chest system is fairly balanced already. If the only chests that refill are the ones at the cornucopia, no single player will stand a chance, only those in a team.
I'm not certain as to my opinion towards only weapons spawning in other chests. While it would force people to the cornucopia, the team that holds it will still have an unfair advantage.
If this idea is implemented, to not have any food spawn in the outside chests, then the weapon spawn rate needs to increase. I once hit four chests at the start of a game and didn't get a single sword, leaving me defenseless the first night despite the food and armor I'd stockpiled.
Only the cornucopia chests is not the solution in my opinion, but if the outside chests only spawn weapons and armor than the rate at which weapons especially spawn needs to be increased, and some more crafting tables should be added as well. This way those not holding the cornucopia have a chance to get armed even if they don't get lucky enough to find a sword.