Relates to: MC-278783 MC-278784 MC-278785
The bug
minecraft:sculk_shrieker is not present in the Spawn Eggs tab in the Creative inventory. This is despite the fact that they are an item that can be used to spawn mobs. Other non-spawn egg items that spawn mobs are also in this tab (i.e. spawners, trial spawners, creaking hearts), so the exclusion of eggs seems unexpected.
How to fix
Add minecraft:sculk_shrieker to the Spawn Eggs tab. This might have to be a separate item with a component that sets the can_summon component to true so that it can actually spawn wardens.
Sculk shriekers cannot spawn wardens when placed down by a player, as it's NBT tag of "can_summon" gets set to false. This is most likely working as intended. See MC-250137