Freelancer is one of the few games I voted for on GOG. I played through the story mode a few times, played online with friends and tried a lot of different mods. A lot of fans says Discovery, Crossfire and other large mods are the best but (though I love Discovery) actually the small old ones do the real magic like Evolution, 88Flak, and Nomad Revenge.
It would be possible to restore the master server for the game just like what happened to Battlefront 2. If that happen GOG could run a server with the Evolution mod (because that is the closest to the vanilla games, actually it do nothing other than enabling the usage of all the ship from all the classes).