In the 1.16.210.58 Beta, the player_firstperson.animations.json was updated with a new variable: "animation.player.first_person.attack_rotation_item". However, upon changing some values under "rotation", it only changes the attack animations for items that change state, such as the bow, crossbow, trident, and shield. It does not change the attack animations for other items like swords, food, snowballs, and blocks.

Update: Affect 1.16.210 update,