Colin Johanson doesn't think the MMO is dying. He would say that: he's the studio head of Arenanet, the team behind the Guild Wars series. He's also talking to me directly after showing off combat and movement in the team's next MMO, Guild Wars 3. That said, what is more unexpected is that he says the genre is "as big as it's ever been."
You just need to expand your definition of an MMO.