Helper To Hero will return.
The return of Helpers makes the return of this mode obvious. It could even support multiplayer. The game will borrow heavily from the Dark Matter Trilogy.
In particular Kirby's Dream Land 3 and Kirby 64: The Crystal Shards. We're already seeing many Call Backs to those games, such as the Clean Ability and Ability Mixing. The game will borrow more music, enemies, and motifs from those games than previous Kirby games. Dark Matter itself is the antagonist.
The game seems to have love and friendship as a theme, which can be seen in how you get Helpers, the ability combinations and that wheel combo thing. Love and friendship feature heavily in Dreamland 3 and Crystal Shards, both of which are part of the Dark Matter trilogy. In addition, multiple features from both these games are returning, such as Clean and Ability Combinations. And Whispy Woods is shown with a suspicious dark haze around him, as if to imply he's been possessed by a dark entity...- Alternatively, a Dark Matter Expy (such as Dark Nebula) will be the main antagonist. Besides... I think we're getting tired of the tradition of having new, limbless villains. Also, I highly doubt that it's Dark Matter. It's possession color appears to be black, not purple/violet.
This game will focus on The Power of Friendship (and maybe The Power of Love).
Like Triple Deluxe focusing on flowers and nature and Planet Robobot on robots and machines, this is highly likely. And yes, I am aware of Kirby's Dream Land 3's Heart Stars and Love-Love Stick, but it'll be more played out here than in that game due to Kirby's hearts converting enemies into Helpers. So it's possible that we're going to get a heart motif in this game.