A server emulator is using the Disney provided client. This would mean no modifications, no bug fixes, nothing of that, on the client side. It's merely emulating what the game was when Disney shut it down on September 19, 2013.
I wouldn't exactly call recreating the game "reproducing the original gameserver," as that would require it to be a 100% carbon copy of Pirates of the Caribbean Online, with no modifications or bug fixes, it'd be exact to POTCO. This is not entirely the goal of The Legend of Pirates Online.
Disney's Toontown Online had a similar thing happen to it. There were the actual servers that brought Toontown back and added onto it. These were not emulators, as they took Toontown Online, polished it up, fixed the bugs and exploits, and then extended upon it for an even better online experience. Then we had attempted server emulators that used Toontown.exe (The Disney provided client) to connect to the game. These emulators proved to not be feasible, as you could not make a fully functional game using them, and you were stuck with Disney's client. This meant the many bugs and exploits present could not be fixed. This is an obvious issue.
To see what a server emulator for Toontown Online looked like, and how it functioned, please refer to this video:
You could expect similar results for a Pirates Online based server emulator that used Pirates_Online.exe (The official client.)