Nah you have it all wrong, Riot still likes their three hit passives but their newer Design Hard On is Better or Different version of older effects.
Camile got adaptive shields because normal shields are too straight forward, Plus her hard lockdown zone
Ornn got his brittle effect, its like cc but lasts longer
Zoe got sleep, because Stuns dont have the connotation of giving more free damage
Nunu got Snowbound, because just being stun means you cant slap AOE magic damage on it without having to make it a new effect.
and Morde has Death Realm, because Camiles Hard lockdown zone still meant other champs can fight you
So my bet is Fiddle is gonna get some objectively better or more complicated version of a Fear, renamed something new with some built in innate damage or something else.
Fiddle gains a new effect Terror, Terror causes the target to flee in the opposite direction to fiddle, any allies a Terrorised champions walks through is feared for 1 second, the target also takes 30% increased true damage from Fiddlesticks stacking up to 50% based on the crows around them, finally the target is disarmed for 1 second after the effects ends.