The master server tracker replacement is still online and functional.
For NWN2, it was necessary to release an update to the CE to disable the GameSpy chat integration so as to still allow the game to show the server browser UI.
It's possible that NWNCX for NWN1 might need to be updated similarly for the server browser integration. When I made the changes to accommodate the latest GameSpy closures for NWN2, I sent a mail over to virusman with details of the adjustments I had to make to NWN2.