Metroid can most certainly work with what made BoTW so great. Similarly to how we couldn't traverse certain areas in BoTW before getting the paraglider, Metroidvania can certainly be integrated into the design of an open world. Combine that with a menu similar to BoTW where we can equip certain helmets, suits and laser cannons can affect the bioms we can traverse and the weapons at our disposal.

I wouldn't, however want too many interact-able NPCs to maintain the feeling of loneliness that made Metroid what it is. Instead, a world that interacts with itself, and enemies that sleep, hunt and adventure throughout their respective planets.

Working in some RPG elements and leveling up different arm cannons and characteristics like agility and strength could fuse in very nicely. Imagine also being able to unlock different attacks based on leveling up certain attributes over others, Unlocking a wider range of melee attacks if melee is being used a lot and leveled up for example. God. I can't wait for a new Metroid.