Piglins raise their arms like a vindicator when wielding certain items:

• Item or a block (besides tools)
• Shield or trident

Per MC-186102 this is not intended behavior.

Steps to reproduce:

1. Spawn a piglin
2. Make sure the difficulty is not set to Peaceful
3. Run /replaceitem entity @e[type=minecraft:piglin] slot.weapon.mainhand 0 shield/trident/gravel/bowl
4. Go into Survival mode

Observed result:
The piglin raises its arm like a vindicator.

Expected result:
The piglin does not raise its arm like a vindicator.