The vast majority of animal spawns in the cherry grove biome are pigs. This is due to two factors:
The pig spawn weight in the cherry grove biome is much higher than the weight of other animals. Pigs have a weight of 10, while sheep and rabbits have a weight of 2 and donkeys have a weight of 1.
Rabbits cannot spawn wherever cherry tree leaves filter sky light light due to their abnormally high light level requirement (MCPE-105222).
Steps to reproduce
Find a cherry grove biome.
During the daytime, run around killing animals for a few minutes.
Expected result
You kill comparable numbers of pigs, sheep, and rabbits, and donkeys.
Observed result
You kill a huge number of pigs, a few sheep, and may not see a rabbit or donkey at all.
A little history:
Rabbits used to have a weight of 20, which is much higher than any other ranimals, in the old flower_forest biome. When flower_forest was updated to meadow, rabbits and sheep were given a separate set of spawn rules for the meadow where rabbits and sheep have weight 2 and donkeys have weight 1. These weights are much lower than other biomes, but since no other animals spawn there they work out fine. The meadow weights were then applied to cherry grove when it was added. However, pigs were also added to cherry grove, but pigs were not give a separate set of spawn rules for the cherry grove like rabbits, sheep, and donkeys have for meadow/cherry_grove. Instead, cherry grove was just added to the old pig spawn rules where their weight is 10. That made pigs significantly over-weighted in cherry groves.