As I've been progressing in Mythic ToS, I've noticed that COF seems to have been nerfed indirectly, both for BM and MM.
On multiple fights, there are adds/burn phases vs normal phases, and this often means I have to hold my Trueshot often for 30+ seconds (w/boots+2set t19) to line up with the next burn phase. Similarly for BM, while earlier BF and Aspect would line up perfectly, I'm now noticing Aspect come off just as the second BW ends, meaning I once again have to hold it for 20 odd seconds (with Wrists + COF). By the burn-phase timers not lining up with our burst CDs, this indirectly nerfs COF (Or rather, buffs other trinkets/procs). I wonder if there's been any real theorycrafting behind this, because all sims will assume using TS/Aspect off CD, but in a real raid environment this is not the case...
Examples of burn phases where I have to hold my CDs:
Harjatan - For tadpole adds on Mythic
Mistress - When adds spawn (This isn't too bad)
Demonic Inquisition - When a number of players spawn adds at once (Mythic)
Desolate Host - When new sets of adds spawn
Maiden - During burn phase with buff
Avatar - For Maiden shields
KJ - For adds (This is mainly for padding though)
Apart from a few exceptions like Spellblade adds, there really wasn't a similar burn pattern in NH... maybe this is Blizz's way of forcing us away from COF.