Well, give me access to the archive then. 'cause the thread is too old to show up in search anymore.
Nevermind, I found it. He changed his name. Here's the quote, and I'll bold the important part for you.
{quoted}
Hard to say, if we made then more clunky it would be easy to brute force, but is the absolute last resort solution. We want to add Gameplay without adding clunkiness when we can.
For Lee Sin, he is just overpowered, so we're bumping him down slightly next patch - junglers are performing very well at the moment and he is the best jungler. (He adds a lot to competitive play though, so we don't want to hit him too hard).
EDIT: Want to bring him down without bricking him for normal and competitive play. Ie. He can be played but he's not in every game. It's not about playing favourites, but just balancing.
Lee is different in that he can be playable in competitive while being fair in normal. Whereas for Amumu and Sej, usually if they're playable in competitive they will probably be unfair in normal play (probably 55+% winrate). We also have some jungle changes that may be going in in the future that disproportionately hurt Lee Sin compared to other junglers. Also I believe that when Lee sin is balanced (but still playable in competitive) he doesn't disproportionately harm jungle diversity in competitive.
Yasuo I'm uncertain on the best course of action, but for sure his laning is very strong, so we could safely take that down and he would end up in a reasonable spot. Not to say for certain he needs nerfs (he is pretty frustrating to play against while being incredibly fun - negates a lot of the things you can do to him). It's interesting that one of the reasons Yasuo needs to have so many tools in his kit is because we don't have turn speed.