The actor did not confirm that he would be appearing in the sequel, only saying, "I assume they'll ask me to be there. In the movie business, you never believe anything. You always assume." Michael Caine also made it clear that Christopher Nolan and his co-writer Jonathan Nolan know who the main villain will be, but they are not sharing that information with anyone at this time.
"It's becoming inevitable, I'll put it that way. I feel myself falling into it, I guess. And getting it all figured out and I'm pretty excited about what we're doing so... If I haven't announced it, I think that people probably all know at this point that I'm doing it. I think (I) can at this point, (say) yes."