^{From MCPE-77698:}
Summary:
All naturally spawning mobs that can despawn should despawn. Naturally spawned baby sheep and baby cows despawn correctly when player moves more than 54 blocks away from them. Baby pigs do not despawn when the player moves 54 blocks away.

Steps to Reproduce:

1. Create a world in latest beta.
2. Wait for baby pig to spawn.
3. Move 54 blocks away from it.

HQ Clip (GDrive) -> Sheep, Pig, Cow

Original Description:
Naturally spawned baby pigs don't despawn when outside the 54 block range, regardless if interactions have been made with them.