I'm not a MAIN of Malzahar but I do quite love the champion and have been sad seeing the changes to him. When I first played old Malzahar, I enjoyed him for a while, but then he just felt TOO easy, since you could just drop an E and take 75% of someone's health. New Malzahar I played a bit more, loved him to death because I love minion mancers and people could still get away from the minions despite building Rylai's so I was fine with the changes, he didn't stomp but he had a chance to. The changes from looking at them(since no one else seems to have actually played them either), seem like mostly nerfs tbh. He gets 20% more AP damage for less voidling damage and less reliability(again).
His Q now from what we talked about on another post is probably going to be pretty crap(despite getting 10% more AP ratio) because of the delays on the ability.
They haven't mentioned if his voidlings will spawn instantly or not from the patch notes so that's also likely to stay as it wasn't mentioned as changed, and his voidlings will likely die from any and all spells at any point in the game since they'll barely have any defenses and barely have any HP(200HP, 50 armor, and 25 MR at level 18), while most mages have one spell that's AOE that can do around 300 damage) and they're sure to be killed with auto attacks, likely before dealing damage because they have no speed boost toward their target. Also considering you'll only be able to have two out at a time I feel the ability is going to be pretty pointless(unless they still spawn voidlings from one attacking, then it MIGHT be somewhat crap but at least bearable)
His E doesn't really do any damage now, and probably won't do much damage again, I can't see 10 extra damage for every 100 AP being a lot considering as Malz you'll be wanting items that don't give a LOT of AP(Rylais, Liandries for sure) as your core build and that will cut your power. Most of the time an AP mid laner has about 300-500 AP. I'd imagine Malzahar being on the lower end of the spectrum with around 300 which would be 30 damage a tick. Not a whole lot considering most of his abilities are probably either going to deal minimal damage or miss(not reliable anymore),
His ultimate is the only really good change, as it's giving him a ton of damage in it, but that's going to ruin all of his other abilities as their reliability has been cut down tremendously and he's going to just be an ult bot. His other abilities will only have a guarantee of damage when he ults someone, and that'll HAVE to be the ADC or his minions will get chopped down before they do anything, and even then if only two are allowed to be spawned at a time it wouldn't take much to cut that damage out.
So my final thoughts, Malzahar is being turned into an ult bot and probably still won't be very good. I feel like they're just giving him less and less reliable damage despite the fact that he hasn't been that good for a while and even when he was good AS A SUPPORT(he was only good as support during that time, so much so that Malzahar mid wasn't even SHOWN on OP.GG as one of his roles), he was at 50% win rate. I'm all for killing support Malzahar so he can be played mid, but I don't think this will make him able to play mid.