Analysis:
It can occur at lower altitudes but it has to be close to the maximum altitude.
This can also occur if the villager is summoned above 320+ this does not happen in Java.
Steps to reproduce:
go to a biome that has a different villager skin than the default one.
Put a block on layer 319 (5x5)
/fill ~ 319 ~ 5 319 5 dirt
put another block on layer 318 and put two villagers and put three beds (5x5)
Now raise the villager to the maximum layer of bread and let it reproduce. (Relates to Baby born skin incorrect MCPE-174227 )
Steps to reproduce (summon entity) :
go to a biome that has a different villager skin than the default one.
go to height 325.
summon a villager.
Expected results:
Villagers have the corresponding skin in the biome they are in. (Only Java edition occurs) Also only if the summon step is done since there is another breeding bug in Java edition (MC-299232).
Observed results:
Villagers have default skin.
Can confirm.