Piglin brutes will not spawn and cannot be summoned in Peaceful difficulty.

This is a parity break as in Bedrock Edition, piglin brutes will spawn in Peaceful difficulty with passive behavior just like piglins.

To recreate: Enter a bastion in Peaceful difficulty and see that no piglin brutes will be present. You can also try summoning them with spawn eggs in Creative mode and will see that no brutes will appear.

I hope this does not end up being a duplicate, but I could not find a similar issue in the search bar.

This affects all versions since 1.16.2 (and its snapshots).