There is a chance for you to NEVER get something that is "available" to everyone.
That should not be possible. That is preventing someone from getting a War Spoil that was promised to be obtainable. Now, other systems have trading which means it IS possible to obtain something you'll never earn. But we have nothing of the sort.
In short, it is the worst idea in the world to half-release a luck-based drop system.
Also, bulletins and faceplates are worth nothing. The thing with TF2 is that you can craft crappy items into metals that are universally worth something. That is why i fear for a trading system. No one wants a lot of the spoils, at least you wont get anything that you might not already have in return.
The trading system on Steam is much better than the current alternative - i.e. nothing.
Some people put value on crap like faceplates or skins etc - so if you traded say 40 of them for 1 Commander you didn't have - you're better off rather than being stuck with 40 pieces of junk.