Maybe it's just me, but I have this feeling that Nolan has some kind of a deal with the studios, coming along the partnership/relation of trust he has with them. Or maybe he has created a deal with them personally, by creating and aplying a guideline to himself.
When I say that, I mean that he sometimes feels the need to make a more classical film, a film that is more audience-appealing, with a more meanstream approach (from example, Tenet here, seems to get closer to Inception than Dunkirk if you know what I mean). And maybe by doing that, it's allowed him to maintain a trust from his public and mostly from the studios, so he can do something less classic and more atypical after that, something more risky, in a certain way.
I don't necessarily mean that the studios oblige him to do that(by a contract) but maybe it's a rule, a discipline that he's created and wants to apply to himself.
I hope you understand what I mean(sorry if my english is bad
), but all that to say that I believe, and I really hope so, his next film will be something more original, risky and atypical, something more new to him (like Dunkirk was), something less meanstream. Don't get me wrong, Dunkirk remains a meanstream film, it's a hollywoodian blockbuster, but it's made with an originality and a approach that we weren't used to see with him, coming from him, we were surprised in a sense.
And I hope his next film will be something like that again, something more "arty" in a sense.