The latest beta/preview saw changes on how damage is taken for players. However, baby hoglins are supposed to attack and deal damage to players, but instead, this was changed in the beta/preview.
How to Reproduce
1. Go to the nether and summon a baby hoglin.
/summon hoglin ~ ~ ~ spawn_baby
2. Switch to survival mode.
The baby hoglins starts to attack you and deals 0.5 hearts of damage in normal difficulty.
They ignore you.