I assume this behavior is related to MC-14800
Developers didnt want to see zombies in the nether and set the value to 0 manually
This is not needed anymore since zombified piglins will spawn zombified piglins as reinforcements.
Also if a zombified piglin spawned as a leader it will spawn zombified piglins thus making this a bug.
To reproduce:
Find a group of zombified piglins and/or summon new ones (without specifying any NBT)
/execute as @e[type=minecraft:zombified_piglin] run attribute @s minecraft:spawn_reinforcements base get
❌ Theirspawn_reinforcements
attributes' base values are all 0Repeat steps 1-2 with any other zombie variant (zombie, zombie villager, drowned or husk)
✅ Theirspawn_reinforcements
attributes' base values are in the range 0-0.1
Can confirm, updated title and reproduction steps.
This also happens in 1.21.1, the version before 24w33a (the snapshot which fixed MC-14800), so this was not caused by said fix. The question is whether zombified piglins are intended to have different reinforcement-spawning rules from other zombie variants or whether their lack of reinforcement-summing was a temporary disability which can now be removed.