Salvage = a system to try and draw players to the new areas. "Therefore it's not an endgame event. It's a system" -ElexiaSalvage = end game event, "Kupowers" is a system to try and draw players back to the middle lands as well as, given the proper selection, help low level players out since Kupowers are still fairly limited in nature even where it's in effect (dungeons still lack mob chests for example.)
Seasonal Event X = system to try and draw players to old areas, as well as help low level players out with bonuses that are limited in nature. "Therefore it's not a seasonal event. It's a system."
Kupowers started as a seasonal event to promote their anniversary, which S-E later lengthened to last permanently.
*But let me make up some new categorization that I can apply to anything in the game to make me save face instead*