Adeleine is of the Dark Matter arc, but that has never involved MK (and the Waddle Dee is Bandana Dee from KSSU) so this is probs a Classic are (i.e. the current continuity).
But we might be surprised.
I wonder if that fifth character in the ship thing is allied or trying to betray you at the end.

I really question Dreamlanders.
Also, did the trailer suggest that ONLY Kirby uses copies? And do the others have unique skills? (also, an option for P1 as MK etc?)
EDIT post trailer - lol MK tags along just coz. I see that super inhales involves Wiimote shaking. Hmm, couldn't really tell about Ultra ability specials apart from inhaling certain glowing enemies. Looks like you gain a little bit in the Ultra bar each time you use it...?
LOL at Kirby inhaling DDD, MK AND Waddle Dee and spitting them out. Screw the boss rules, this is Smash Bros.
I wonder if charas can use each other to throw and attack.
And Copy Essences! (not DX, they're too powerful)
Finally we get to see the cannon and a Kuribo Shoe-like item, which debunks the Leaf Kirby using a cannon by default.
Stone got a copy hat change. Ultra Sword just looks more BA (but we've seen it already)