In mid-June of 2025 (link, SAS), this banner appeared on the Customer Reviews Dashboard (link), announcing the feature’s deprecation - in favor of integration with a planned new capability of the Voice of the Liar Voice of the Customer functionality - on 093025:
A great hue and cry arose among the Seller Community, and, in one of those rare instances of Amazon actually listening to Selling Partner feedback, the plan was rescinded on 090525, when Amazon substituted that banner with this one:
As our friend April astutely alludes, a preponderance of the available evidence strongly suggests that Amazon has now backtracked from the earlier recision for the same reason that the original ability to post comments to Product Reviews was taken away in the first place:
Because Bad (and/or Ignorant) Actors abused the process.