playing devil's advocate a little bit, but wikipedia does have a policy against original research. If you published an obviously correct counterexample to wikipedia which is not anywhere else on the internet (or in a book, etc), the rules are clear: the counterexample must be removed.

in this case it's not original research, because there's a tweet by someone with a good reputation, and plenty of comments on said tweet corroborating the result. But it's a more sketchy "secondary source" than most wikipedia references and some caution on the part of the editors is not out of place.

(saying this as the person who made the original edit to the wikipedia page adding the counterexample)

The talk page about the conjecture clarifies WP:RSSELF:

https://en.wikipedia.org/wiki/Wikipedia:Reliable_sources#Sel...

> Self-published expert sources may be considered reliable when produced by an established expert on the subject matter, whose work in the relevant field has previously been published by reliable, independent publications.

I'm not complaining about Wikipedia here, just noting for the thread: it's a vector of polynomials. It has a nonsingular Jacobian. Provided with it are 3 distinct points it sends to the same point; it can't be invertible.

What Wikipedia says about this doesn't matter, does it?

It's more like WP:BASICMATH. It's like someone showing a huge number isn't prime (proverbially hard to factor, trivial to check) and HN/WP users requesting a reputable source citation for the factor multiplication when anyone can input it in a calculator.

Verifying that counterexample is a trivial calculation for basically anyone qualified to make substantive changes in that category of article, it shouldn't be an issue in and of itself.

Discovering the counter example is research, validating it is basic calculations.

See https://en.wikipedia.org/wiki/Wikipedia:No_original_research...

Wikipedia's editors won't be happy until the site has joined Stack Overflow in self-owned oblivion.