Not to put too fine a point on it, I don't think the first Last Exorcism portrays a single supernatural event anywhere in its entire run time. This trailer for the second film, however… well, there's levitation, at least.
Of course, a sequel can't change the text of the original even while it might ask you to reconsider it.
It perhaps seems counter intuitive for a film that rejects the supernatural to be followed by one that embraces it, but there's no good reason this shouldn't be the case. If anything else, it suggests that the films are that much further apart, preventing the second from just being an echo of the first.