Plays it a little too safe. Deathmatch is way too simple to be a big selling point of the game. Not even the name of the mode just "deathmatch." I can certainly see a mode like it, but where is the new unique mode only Splatoon can provide?
More examples of playing it safe is mentioning the Arcade and amiibo. Of course those are possibilites to show up. Notice how this person doesn't go into much details about what these are for and can do. Like does the arcade give you anything? Does the Mario cap have special stats?
Lastly, as much I would love to see these stages based on these franchises, I'm skeptical of Kirby after things like Nintendoland. I expect something like G&W or Yoshi first to be honest.
It would certainly all be neat to see, though it wouldn't be the most mind blowing direct.