This guy is lying, isn't on the latest version, or is using an older hardware AP.
Tesla has essentially fixed phantom braking as of 2021.4.15, at least with AP enabled. I would think TACC wouldn't be that far off.
It was still pretty frequent up until the point where I moved from HW2.5 to HW3, which was... maybe October? Some time in the last half of last year, anyway. I doubt it has gotten better on HW2.5.
But yeah, it definitely seems better with HW3.