Zombified Piglins don't lose aggression as it is in previous versions. I tried waiting for aggression timer to expire in 35, 60, 100+ blocks, other dimesions, using invisibility potions etc., but in 1.21 zombified piglin aggression is bugged. I've attached a google drive folder containing footage of versions 1.20.4 and 1.21 filmed in the same world with same timings. In 1.20.4 zombified piglins stop becoming hostile, as oppose to 1.21: https://drive.google.com/drive/folders/1Dyab3FXRLF_dyCLLlyiI7VaWwqSXXq6T