I'm not sure that anything actually needs to be changed about the definition, here. It's about endings that are presented as happy, but aren't interpreted that way by the audience. Pretty straightforward (although we might want to include a disclaimer a la The Untwist
's, where any ending can become unhappy to someone sufficiently determined to see it that way).
There's definitely some misuse, though. Seinfeld
is listed, for example, and I don't think that anyone was supposed to believe that "all the main characters get sent to jail" is a happy ending.
I'd suggest rewriting the description to make it clearer (without actually changing the definition) and purging bad examples. I don't think we need to do anything else, here.