Hot take, but I'd rather have Beyond resemble Corruption than Prime 1 (I'm sorry, ItWasMeantToBe19). I love both games roughly equally, but I'd be pretty disappointed if we once again got Zebes / Tallon IV type biomes like your typical forest, lava cave, and snow area. I've personally had my fill of those, and I'd prefer to see more alien / creative areas like Sanctuary Fortress, Elysia, the Pirate Homeworld, and Phaaze. Those are simply the peak environments of the Prime series, and there's nothing like them in the 2D games.
I also much prefer Corruption's combat, and I'm hoping they're meaningfully iterating upon it. Please let Samus have a dash or a slide, plus a melee of some sort.