So what is Malzahar supposed to be riot?
So this is a shift of the discussion on Malzahar's objective taking ability highlighted here http://boards.na.leagueoflegends.com/en/c/gameplay-balance/JqqluM9Y-the-malzahar-change-is-workable-except-for-1-part to talking about what exactly is Malzahar's identity as a mage now.
Before the 6.23 change I would have Malzahar under control mage (or disruptors as you call them) by putting e-w on a frontline tank and refreshing with q you would wear them down quickly. It really made it hard to dive on to Malzahar's team and was a nice niche (minion summoning peeling/kiting mage). He can obviously still attempt to do this, but the problem is champions like Nasus who used to be voidling fodder for Malzahar now can kill voidlings with just his e over 2-3 seconds (less with ult on too).
Even if he couldn't kill them easily they are now slower if Malzahar isn't within 600 units of the target Nasus could honestly just walk away from them. 600 is also a pretty short range for a kiting mage to be within, especially if the rylai's nerf goes through and the slow is worse. He really doesn't strike me as a battle mage with his low defensive options, he basically has q and r since a sneeze kills voidlings and pops passive.
So what is left for Malzahar to do effectively? He can't farm or trade as effectively as he did before, he can't dish out damage in teamfights reliably anymore (this is completely decided by his opponents which also feels bad), and he can't meaningfully contribute to objectives either. I mean you went completely against your rework design of focusing him on being a pet summoner play style. All he does now is hope he doesn't get camped and try to roam with
r. I'm honestly uncertain if he still works as a general assassin counter, something like Leblanc might be ok (though she can kill voidlings like everyone else). Something like Fizz however can kill voidlings easily early and break his shield post 6 with r now since it applies w passive then kill him almost immediately with follow up.
I don't see why you felt it necessary to implement what amounts to a laning phase, a team fighting, and an objective control nerf all at once. I mean riot responded that they felt his voidlings tanking objectives were unfair. You know what a reasonable response to that would have been? New passive on w "void friends - baron (and dragon) no longer target voidlings" if the damage was too high you could reduce voidling damage to epic monsters.
I'm at the point where I am about to start ranting so I will just sum up my ideas and wrap it up. Malzahar will probably have a not horrible winrate after this, I'm thinking 47-48% (maybe 50 if people adapt quickly to being an r bot) but he has lost his uniqueness for some unlikely extra burst. Basically he is just going to feel bad to play due to how clunky he feels and how much his damage is reliant on his opponent misplaying.
Tl'dr - Malzahar's voidlings are too weak to make him a control mage, he is too weak himself to be a battle mage, and he certainly lost his unique style of voidling swarm summoner that was the goal of the mymu.