The Bug:

Sculk sensors are not activated upon falling into a sweet berry bush

Steps to Reproduce:

• Fall into a sweet berry bush. (You must not have any horizontal motion whilst doing this).
  →  Notice how upon falling into a sweet berry bush, sculk sensors are not activated.

Additional Information:

Quote from the 20w49a Changelog, "A vibration is anything that causes physical motion". I would definitely consider this as physical motion, as you are physically hitting the ground.