The poster is making a positive claim without evidence. Indeed the claim is unverifiable.
Reasonable priors lead fo a null hypothesis that they are at least simply mistaken.
This is without even taking into account other indicators of credibility or authority, or perverse incentives, as priors.
This is a rational use of ‘null hypothesis’, but it also matches the scientific use, which would be that the claim is spurious unless experiment shows otherwise.
In any case, we know that the poster is in fact wrong in their claim.