I just post the comment I did on Andres youtube page one month ago about the Warden AS/PK dpendance and his following answer which I think complete well his video:
Hi Andres, I think you're missing something about anti-squat: AS is positively correlated to pedal-kickback, meaning high AS = high PK.
When you state that under pedalling, suspension might not be fully active to bumps, it is also true when your are NOT pedaling since suspension compression under bumps will generate pedal kickback, i.e., vertical, top directed motion of the right pedal under suspension compression.
Since you are weighting on pedals, and due to the vertical, ground directed component of acceleration that you encounter during a jump reception or after the summit of a bump , and that is transmitted to the suspension through pedals, you're just partly blocking the suspension action.
So high AS basically interferate with suspension action even when you are not pedalling, and prevent the suspension to act as it should.
Answer from Andres:
Your rational is totally right. However, that's mostly valid when you are at a static position or at slow speeds (eg: climbing). At faster speeds the chain growth will mostly make the rear free hub to rotate forward, instead of rotating the pedals backwards and lifting your weight (the wheel is already spinning fast, so the chain pulling will just make the cassette to rotate forward and you wont feel nothing on the pedals, in this case the suspension is almost free to move). At slower speeds you will feel more the kickback because the cassette can no longer freely rotate forward because that would cause acceleration to the bike. Since that you mostly stop pedaling when you are running faster (eg: descends) in practice the kickback is mostly felt when you are pedaling and the chain is under tension (specially on technical climbs).