Riot for the love of god think before you make changes
Cinderhulk was not a bad update. The problem is that it is such a strong item that it is being built on laners. (Remember what happened to old jung items when they were better than the laning versions)
This means that top lane is now running smite because of an extremely broken item. Hell, Cinderhulk outscales Sunfire straight from level 1. Now when you get this at around level 6 you already have a huge advantage over the item.
Going to extremes has caused there to be several perma ban champs.
. Notice a pattern? I do. They are all tanks that were doing perfectly fine at their jobs before Cinderhulk. Some may not have been common picks, but they were strong nonetheless. Some are still under the radar even now, but with Sion and Sej seeing a lot of competitive play and becoming perma ban its only a little while until we see Maokai, Skarner, and Voli being pulled out to get around that. Then you have 5 perma bans that are all tanks.
Now, I do admit Voli has counter play, but Cinderhulk makes his window just too small. Skarner is not a big pre-6 gank champ, but he does excel at counter jungling pre-6. I would say more about Skarner as he is really strong, but I have not played him enough to really be able to have any good input here. He has been really strong every game I have seen him, and my friends who have picked him up during free weeks have stomped with him.
Maokai has had many issues in the past since his rework and Cinderhulk combined with his new ult are a big issue. His new ult costs too little and can be active for too long and does too much damage for its low CD and mana costs. 10s is a long time. And to be absorbing damage so his ult can put out a bare minimum of 400 damage in an AoE when he is meant to stick to people is stupid when he already has a tank shred gapcloser, a sapling with a slow, and a slow and knock-up in one ability. Cinderhulk makes it so you literally cannot go anywhere within his gapcloser range if you are a squishy. You will die before you can even have a chance of escaping because you will be chased down.
I really think that as good as Cinderhulk is for tanks, it poses a real problem because it synergizes so well with CC and stick potential which is something almost every tank has which is bad for the health of the overall game.