That's the analytics API. We already know they show dislikes to the channel owner. Isn't this the same thing?
And your other comment says "The dislike count is also still present in the [0] video API response." but the page says right there "Note: The statistics.dislikeCount property was made private as of December 13, 2021."
[0]https://developers.google.com/youtube/analytics/metrics#disl...