Heck no it won’t.
Mortick’s doesn’t offer damage since we already take Insanity. EF won’t offer damage, either. The point of T16 is to kill things quickly, not build stacks of attack speed.
The problem is, and always has been, damage.
A few of these items might make their way into speed-farming builds, but even then they won’t be buffs so much as lateral item choices.
For Zodiac WW, you could take Executioner in the Cube, but is it better than Furnace? Not if you have to make multiple passes to kill an elite. Better than In-geom? Not if you have the damage to kill things quickly.
BTW, on the topic of Mortick’s, here is exactly what it’s going to offer us by build:
Zodiac WW: Could replace PoC and Ignore Pain, but only if we wear it vs Parthans. Even then, there’s no other good skill to put on the bar (because there’s no good supporting legendaries to support our skills). So, at best, we’ll assign the slot to Falter or Spring and use it for speed-farming.
We won’t use it for pushing because we can’t give up the damage from Mantle in the Cube and Parthans offers more mitigation.
IK HOTA: It can replace Aquila in the Cube, but so what? 50% DR for 50% DR? It’s better than Aquila, but only because it’s more consistent.
R6 HOTA: Won’t use it since the build doesn’t maintain perma-Wrath and can’t give up the better mitigation offered by Aquila (or the DPS of Magefist).
Vile Charge: Parthans offers better DR for pushes, so it’s not likely to be used except in speed-farming.
Fire/Physical EQ: Won’t use it since the builds have low uptime on Wrath. Besides, these builds are already tanky.
Our minor builds? None of them have perma-Wrath.
LON builds? They’ll have to take Boon, 50% CDR, and possibly Messerschmidt’s in the Cube. But if you have 50% CDR, why not just take IP and wear PoC for the exact same bonus?
Point is, Mortick’s offers us nothing of substance.