this just referring to lowering the in game sensitivity in games?
They're talking about with the last 3 COD's you can lower the ADS sensitivity multiplier. This separates Hip and ADS sensitivity in game.
Honestly though, this all looks, smells and feels like placebo though. You can create the same effect by simply lowering you XIM ADS sensitivity.
The best thing for AA maneuverability with the last two COD's is Linear type curve IMO.
I can't vouch for Cold War specifically, but I do know that the original Infinity Ward (now Respawn) has always made their AA values decrease with increasing controller sensitivity. I've unpacked the actual files from Titanfall, Titanfall 2, Modern Warfare 2 and 3, and it was always the same basic concept. As sensitivity increases, the base aim assist values are decreased. If they didn't do this, then everyone would run max sensitivity with controllers and it would essentially feel like an aimbot.
I experimented with those values and repacked the files for offline testing (going online would get insta-ban for file checks). And it made a lot more sense why they do it.
TL;DR= it's common practice by COD developers to lower aim assist values as sensitivity goes up, for sake of balance.