The bug
Parrots don't imitate sounds of bees in 19w34a although bees are considered neutral mobs.
Linked issues
relates to 1
Comments 3
If it is intended, why do parrots now imitate the sounds of pandas? (Resolved as 'Fixed' at MC-138078). But that's not all, parrots also imitate wolves and polar bears.
Probably intended, parrots don't mimic other neutral "animals", like llamas (yes, parrots not mimicking llamas is working as intended, see the resolution of MC-141071).