Every since December of last year, when a certain movie came out that became very divisive among fans because of how it subverted expectations (tell me if I'm being too subtle, jk) and it has spurred a huge conversation around subverting expectations. If you need proof, just Google "subverting expectations" and you'll see exactly what I'm talking about.
Personally, I believe the best example of how to subvert expectations the right way comes from A Study in Pink, the first episode of BBC's hit show Sherlock. If you haven't see it, 1) you should, it's a fantastic episode of a fantastic show, and 2) be warned that there are spoilers ahead. Here is the scene that is a perfect example of how to properly subvert expectations.
Every aspect of this scene, from the setting, to the background music, to the conversation itself, is meant to make us believe that the man Watson is talking to is Moriarty, or at least to some kind of villain. But he isn't.
When John says "So he's not...I don't know, a criminal mastermind.", he's not alone. That is exactly how the audience is supposed to feel. The man who we had every right to believe was a villain turned out to be just a concerned older brother.
And that, to me, is how to subvert expectations correctly. You lure the audience by making us believe we know exactly what's being set up, and then find a clever way of pulling the rug out from under us. In other words, make something original out of a preestablished way of setting up audience expectations. That is how you do it right.
What do you think are some other good examples of how to subvert expectations? What about examples of how not to do so? I'd love to hear from you down below.