When 2 villagers mate in the Gravelly Hills Biome, they produce a Plains Baby Villager, despite the fact that the villager outfit for that biome is the taiga variant.

Steps to recreate:

1.  travel to a Gravelly Hills biome
2. Place 3 beds, 2 workstations, and a bell
3. Spawn 2 villagers (they should spawn as the taiga variant)
4. Give 3 bread to 1 of the villagers
5. Wait for them to mate

Expected Result:
The baby villager produced is wearing the Taiga biome outfit

Observed Result:
The baby villager produced is wearing the Plains biome outfit

This may occur in other versions, but I can only access the latest release version of MCPE.

Seed: -8737485652328590736
X: 21443
Y: 90-ish
Z: 6741