The bug
Sculk sensors can spawn from sculk charges created by catalysts. Sculk shriekers used to be able to as well, however this no longer seems to be the case. The changelog does not seem to have stated that the ability for them to spawn has been removed or changed, so this is very likely an oversight of some sort.
How to reproduce
Create a new default Superflat world
Teleport to (0, 0)
Place four sculk catalysts at (-2, -60, -2), (-2, -60, 2), (2, -60, -2) and (2, -60, 2)
Place a repeating command block at (0, -62, 0)
Set the command to /summon ravager 0 50 0
Place a redstone block on top of the repeating command block
Place lava on top of the redstone block to reduce lag
Observe
Expected results
Both sculk sensors and sculk shriekers would appear in the spreading sculk mass.
Actual results
Only sculk sensors are generated.
in 22w13a, this no longer occurs!