It's more that momentum-based defogging means that the peeker has control over how to manipulate the server's prediction, whereas the victim who is already disadvantaged by network latency now gets an additional penalty of the movement initiation being not telegraphed.

To solve this, the fog of war would need to use purely positional near-edge tolerances, which defeats the entire purpose of fog of war to begin with, which is the pre-aiming reaction time advantage of tracking the peeker through walls in addition to having a farther lever point from the cover than the peeker.