Trynd and Yasuo are going to be indirectly nerfed. Look up pbe changes on surrenderat20, Warlord's Bloodlust is being changes so it works only against champions. I think this change will be enough to put them again in right spot, if not, I'm sure Riot will take additional actions to balance them properly.
When it comes to tanks, they are in pretty good spot. LW nerf made building armor more effective against AD champions, as well as Banshee and SV were buffed, so mages are kinda fcked there. Althrough I'll agree that Cinderhulk needs some love. While lane tanks and tanky supports are in a good spot right now, the same can't be said about tank junglers, they need some help. I would increase health amplification by 5% (from 15% to 20%), and make Immolate passive deal more damage to jungle monsters to help them with clearing.
I'm gonna 100% agree with you about mages, at least those who use mana. Removal of mana potions hurts some of them, increasing cost of AP items was just cruel and buffs to MR items is adding insult to injury. Poor guys were nerfed in 2 or even 3 ways (depending on champions) - early mana sustain (for those mana hungry), needing more money to get mid game power spike and having problems with killing targets because MR items were either buffed (Banshee, SV) or made more attractive (Merculiar, Malmortius).
But again, it needs to be reminded: this is preseason. We will see some OP crap for next month or so, it cannot be avoided. Some forget that it is normal that game is slightly broken at this time. Don't u remember 4.20 Warwick (such a perfect patch number)? One shoting with ult with only Devourer, BotrK and Wit's End. That was crazy. Guess what, he was nerfed back then. The same applies now, Graves and MF are getting nerfed, Warlord's Bloodlust, which made Yas and Trynd broken is getting nerfed... Relax and give it a time, as soon as preseason ends, everybody will forget that all these OP things existed.