Ok, this probably isn't a bug, but the warden should probably also emerge from other entities. Being a warden, it would protect the deep dark from everything. Not just the player.
Linked issues
relates to 1
Comments 2
See MCPE-152856.
MC-252101
Only the player can activate a shrieker
Resolved
Works As Intended
2
Relevant snapshot blog post: https://www.minecraft.net/en-us/article/minecraft-snapshot-22w12a (Text fragment link)