Since DnD as a brand on its own is getting stronger, it would make sense for a studio to take over the license as a whole and as its identity.
First of all this is not going to happen because WotC itself is not going to want this. They have very ambitious plans to release at least two D&D-based video games per year, and you cannot do that with just one studio making those games. That's why right now they have at least four different studios working on D&D games.
Secondly, as a fan of D&D games, I would NOT want just one studio working on D&D games because then I am stuck with whatever is the game vision of that one studio. And if that vision is not my vision, then I am screwed. Using Larian as an example, if Larian is the only studio making D&D games, then I will never get a RTwP D&D game. And that would be outrageously unacceptable to me.