The Wits End changes won't make the item purchasable for most champs
Wits end is already a niche item. MR, AS, on-hit magic damage. With the PBE changes, its losing its MR shred/stacking for a heal when on low health. (aka Warwick passive)
The thing is, for the small pool of champs that would actually want to build this item, they have others that they want more.
Who could possibly (really stretching possibly) want to build 
Kayle wants other items sooner, and she already maxes out on attack speed. And Kayle now goes either full crit AD or AP with some AS, no longer does she go on hit. Kled, along with most other melee champs on this list, would go Titanic over Wits in 99% of games. Master Yi might as a sixth item against high AP teams. Riot killed/is trying to kill on-hit neeko, since she is supposed to be a mage. Nunu has a jungle budget and doesnt really build damage, if he was going to titanic is better on him. Shen goes titanic into tank. He might pick it up, but unlikely. Shyvana goes titanic. Teemo would prefer old wits if he was gonna build it for the MR shred. Varus already reaches AS cap on his current build. Volibear would go titanic, if he saw play. Warwick already has the passive, and is the most likely to go for it, but he builds tiamat before his jungle item and goes into titanic, it would have to be a 4th or 5th item. Xin wants TF or BC, i dont see him getting wits.
I like the idea Riot, but in an already small niche you have to really make the item stand out, or remove others from its niche to make it stand out
+ 
for his first two buys. In the worst way. after that he needs 
and then he can go into some combination of 
builds 
