Good questions, Viridiana.
Indeed, you could write stories which play against expectations. "Oh, *that's* surprising! I didn't expect that! The story did *not• give…
Good questions, Viridiana. First off, it's not a rule. I don't believe there are any rules when it comes to Hollywood storytelling. There are conventions and expectations, but no rules. So the convention may be, "Give 'em what they expect, then give 'em what they want," but that doesn't mean a writer *has* to craft a script that way. While it may have proven itself to an effective way to end a story, there is no set pattern which mandates a writer that way.
Indeed, you could write stories which play against expectations. "Oh, *that's* surprising! I didn't expect that! The story did *not• give me what I wanted." It can work.
Bottom line, do what you *feel* is write, the most honest and compelling way to tell *your* story.
That's my advice.