Empress Defeated (in kMST)

There have been no server source leaks of gMS. The only code that's been "leaked" was that code that kMS accidentally put in the .wz files in a kMS(T?) patch a little while ago.

Basically this. Private servers are only made to look like they mirror the real server. It isn't very difficult if you've got someone who's good at Java. There isn't very much that can't be altered, added, or removed as far as private servers go. Last I knew of the only real thing that couldn't be was added/removed was jobs/skills.

Not really relevant, but I believe that the Zakum quest scripts were leaked a few years back.
I think even fiel might have posted them, but not sure.
The pserver has fixed bugs that plague GMS, such as dark meta, empress, cwkpq(before official) etc, so it is shown that they can fix these bugs.