This would be cool. Not going to happen as it defeats the whole purpose of the keys, which is to force everyone to buy c-points to unlock the boxes which I imagine will be fairly common drops. It's yet another way that Cryptic is attempting to take advantage of their player base like they did with the holiday boxes.
To be fair, however, they did tell us this was coming. Still... I'll leave off by repeating that I think a "master key" would be a great incentive for Gold accounts. Thanks.
They won't give us free key's or a master key, this game is F2P which means they will try to make as much money as possible. This is where getting a 20% discount in the c-store for gold/lifers would be a boon. They could easily add it so it doesn't stack with the other sales they've had in the past.