Already, the different behaviors for silenced/unsilenced weapons works in the scritps...but it's impossible for a Classic server to operate if people can pop the silencers off of PP7-S and D5K-S for the accuracy boost, and making U/S match would remove the guns, again killing hopes for Classic servers. The only way to get it right is to do it right. That being said, I do support toggling being allowed as an option. Scenarios like YOLT, especially in properly designed maps, could make stealth a real option, and make silencer toggling a gameplay mechanic, rather than a way to annoy people with little pew-pew-pew sound effects.
The canon weapon sets were designed with silenced/unsilenced's differences in mind -- I don't see why GES couldn't support specification of U, S, or Toggleable weapons in a weaponset, or at least specify U or S on pickup, and have an sv_ that may allow or deny switching form.