Last I remember MasangSoft owned the licensing to Priston Tale.
I'm not too surprised that the server closed to be honest. Getting into legal cases with companies from foreign countries does not seem worth the time investment for an all but dead game in a rapidly decaying genre. That's actually a really big hit overall though, because I can't really see anybody who played RealmPT joining Suba's server.
Unfortunate but that's what happens when a game gets neglected for ten years and the player base is the exclusive reason PT is even still alive.