Ughhhhh. I don't like winrate balancing....
" Oh no, it's 3 percent above tolerance levels! I know it's not gonna be a popular move, and will cause pain point over there but now we have to act."
Sorry for the grouch-a-phrase. But. I am curious about this though.
You said his winrate was very high up to around silver (so presumably starting from bronze), did even the players you were addressing the pain point for Want Yorick nerfed? Like, if you were to randomly poll a large sample of those players in all the regions before the changes would you have gotten a majority that said " Yes, Yorick is overpowered." or more importantly " Yeah, Yorick should be nerfed."
I mean I will concede this point if such data were to say that those players said they wanted him nerfed or if on these boards actual non-smurf players of the skill ranges in question who recently played games with Yorick agreed bellow (feel free to speak up boards!). Even if (or especially because?) them being players that read the boards would make them a small subset of players with their opinions influenced by the boards (whooaa!). ( And I'm not even saying you need to collect that data)
Don't play the, well Yorick wasn't popular enough to cause major influence to those player's opinions. If that's the case then was it actually necessary to take action yet then?
Another Yorick thing I had been annoyed about at some point. When his rework came out I saw an early Riot quote stating they did not believe philosophically pet micromanagement was a fit in League. So you're just choosing not to offer that. For even one champion? You're basically deciding for your players that that's not a fun way for a someone to play the game. On an unpopular champion. And. It'd be a tougher sell on a brand new champion maybe (or maybe not, maybe it's just more difficult to convince your marketing department that). I mean. Okay. It could be annoying.
I mean. Maybe it is right. But idk.
But it's just so hugely disappointing for me because his ult creature is really cool (and could be even cooler mechanically). But the AI is sooooooo dumb and limited. Hardly effective against competent players. Only contributes if you manage to pin them. And in this age that's just instant death anyways. I just instantly knew this champion's fate when I read that. And his wall. That you can destroy cool. Interesting. Fine. Not a breeze to aim (approve actually. skill) But there is this thing called Trundle pillar in the game. Like. Huge range (at the time?) No aim required. Indestructable. Absurd slowing. Also has an ultimate with basically no counterplay. Oh no! He compared the abilities in separate kits. That's blasphemous. Come on though. You can so long as you're intelligent about it. How do you expect someone to balance and create all this game then. You don't? Anyways. Like. Is there any wonder why Trundle kept surfacing in competitive matches. Counterplay issues. Yorick's the opposite.
But yeah. In my opinion since Yorick seems to have a really effective skill floor maybe the micro bad and no fun philosophy should be reconsidered.
I confess though. I'm sure Yorick's nerf wasn't too significant. I don't even keep track anymore.
I almost went on another Tangent you probably wouldn't want to read. But the sum of another thought. I think maybe it's time to consider the cow isn't sacred anymore and try major changes to like summoner's rift. The puzzle feels solved. It's no longer a puzzle anymore. It's a test who can perform the solve faster (but in the case of the game better usually min maxing unfairness). I guess it's pretty risky though. Maybe a graphic update again at least. You have just a few maps.
Or at least bring dominion back. And try cross server matchmaking to keep smaller modes alive (I know the tech guys maybe shake their head grinning at such an idea). I know it will be a trade off of lag. Worth it for less serious modes imo. Maybe cross server potential might have other unexpected benefits.
and 
cause 
showing off in top lane ,but ofcourse we won't nerf urgot so it doesn't show clearly that we don't like new picks into world so we will just buff 2 toxic champions and one of them already got buffed from few patch 
that is toxic in my eyes due to his easy to spam ult going to get buffed early on his R for more easy flashy kills, so let us destroy 
by direct nerfs and push the two toxic champions power up 
and 
doing the same job as him in low elo yet that is fine by game balance?
getting nerfed