Perhaps the publication should look inward, not outward, and realize the lines between misinformation and satire are paper thin. Somehow, and perhaps its branding, The Onion manages to maintain humor and absurdity with very little room for interpreting it's content as anything but satire.
There are plenty of people who don't find the onion, at all. It's not a justification for blacklisting them as fake news.
The Onion is, literally, fake news regardless of whether one finds them funny or not. The question is whether people think it's true not whether they think it's funny and that's the only decision being made by a fact-check.
Forum users posted the article from BB asking for it to be debunked. They haven't posted a request for articles from the Onion and that's likely because the Onion is well-known enough for people to know it's satire.
You guys are reaching so hard here.
But a lot just turns on being juxtaposed against a prerequisite belief that's not universal. If you don't share that belief, it won't be funny to you. That doesn't (necessarily) make it bad satire.