So is there any plans for proper Fizz changes in the future?
He's still basically just rotting away in his own little corner thanks to the mechanical issues introduced into his kit with the Assassin rework. So far it also feels like he's been given meaningless buffs in an attempt to please the fizz community and keep them nice and quiet.
He suffers from his own mechanics countering him, horrible itemization, and is countered more and more each day by an insane amount of items and summoner spells. At this point in the meta there's not even a reason to pick fizz beyond simply wanting to play him. Other assassins FAR outclass him and do everything he can possibly do, but better.