The Bug:

Sculk sensors are not activated upon shearing sheep, mushrooms, snow golems and pumpkins.

Steps to Reproduce:

• Shear a sheep.
• Shear a red or brown mooshroom.
• Shear a snow golem.
• Shear a pumpkin.
  →  Notice how the sculk sensor does not activate upon doing any of these things.

Additional Information:

Quote from the 20w49a Changelog, "A vibration is anything that causes physical motion". I would definitely consider these as physical motions, as you are physically performing all of these this tasks.