Blizzard has decided to massively nerf the drop rate of Ancestral Uniques in Diablo 4 Season 8, removing the bonus rate and dropping them down to the same rate as Legendary items.
Patch 2.2.0 PTR Patch Notes Season 8 Blog Post Season 8 PTR Campfire Chat Summary
As recently as the launch of Vessel of Hatred, Blizzard adjusted the drop rates of Ancestral Uniques to be three times as high as they once were.
