I can see your point - but to me it seems you're thinking about stickers mostly as a feedback function for the individual user/post, which is what these are largely used for on "new" social media - when their connection to the "highlight" feature is what's really important to the archival nature of this old school form of social media - a forum.
When you click through highlights, a brief glance at the stickers will immediately tell you whether this highlight is due to its informative nature (lots of I), because the person is a retard (lots of dumb, autistic, MATI), the post states an opinion many agree with (checkmark), the post is genuine crazy (lunacy, autistic, islamic) or because the post is funny (winner, drink, feels).
Having every single nuanced emotion represented might feel necessary so that you can give a reaction closer to your own feelings, but it in no way adds to the broader point of stickers - informing others of the content of the post before they've fully read it and ensuring that posts most worth reading are added to the highlight feature.
As such, I don't think there's any reason for a "haha funny" reaction, because when you think a post is funny, you either like it because it is funny (like reaction, +1 score), or you think that post is so funny, it's a real goddamn winner (winner reaction, +2 score).