In 1.16's development, a change was made to zombified piglin subtitles: "Zombified Piglin angers" was changed to "Zombified Piglin grunts angrily", likely to fit in with other similar subtitles (e.g. "Llama bleats angrily", "Bee buzzes angrily"). However, there are a few remaining cases of "angers" remaining in subtitles, which doesn't exactly make sense, as "angering" isn't exactly a sound. These should probably be changed in similar ways to the above example.
/playsound minecraft:entity.fox.aggro block @p - "Fox angers"
/playsound minecraft:entity.wither.ambient block @p - "Wither angers"
/playsound minecraft:entity.parrot.imitate.wither block @p - "Parrot angers"
Can confirm.