The death of an MMO, while uncommon, is not unheard of. The death and rebirth of an MMO is another matter entirely.
Certainly, some MMOs have seen drastic overhauls over the course of their lifespan: perhaps most notably, World of Warcraft with its Cataclysm expansion, which sundered and reshaped the old world, but kept the core gameplay systems intact. The now-defunct Star Wars Galaxies is probably the closest an MMO has come to being completely remade, but the update that did so, dubbed the New Game Experience, was much-maligned and arguably sent the game into a death spiral.
