are the changes to Miss Fortune power nerfs or power neutral? are they targeting adc MF or support MF?
ADC MF is only strong because sorcery is strong...
and MF support is only played because she has lane priority when coupled with Jhin or Ashe and pros value the first turret a lot. She isn't even good in pro play past the first turret cheese, she falls off harder than a rock.
Imo, what you need to do is target her support position with power neutral changes, her E is fairly obnoxious at level 1-6, but that's the extent of it. Gotta find a way to make that E spell less obnoxious without taking too much power away from it, maybe by pushing back the damage it does over time to the last tick only, so it's not as effective when used solely to poke unless the target is also rooted or stunned. Say, instead of slowing the target and dealing damage every 0.25 seconds for 2 seconds, it slows the target every 0.25 second for 2 seconds and only then deals damage after 2 seconds. Or something like that.
EDIT: also something that might be worth looking into, arcane comet and MF E make it rain have a wonky interaction and her E will trigger arcane comet cooldown reduction effect multiple times I believe to as much as 40% cdr if it hits one player, up to 100% if it hits more than 2 players (it's 10% per enemy hit every 0.5 second, it can easily reach 100% if her E hits more than two players), which is probably not intended.