Elder guardians and brutes should not despawn in peaceful

If you’re in peaceful and go by an ocean monument or bastion, these mobs will forever despawn and will never reappear. Either have a way for them to respawn or have them like shulkers where they become peaceful so you don’t lose them forever accidentally. This could be very frustrating for new players who might start in peaceful and then realize they’ve forever lost out on the chance to get valuable resources without finding a new structure or rage quitting.