If there is one thing that I've learned since I started looking at the forums, it's that these people are terrible at predicting what's going to be strong before it's released.
Remember the juggernaut update? Remember how fucking everyone said Skarner and Mordekaiser (the other two got this treatment as well, and in Darius' case they were right, but these two in particular got shit on) would be utter garbage, and that they'd need serious buffs?
Then the patch drops and Skarner has a ridiculous 62% win rate and Mordekaiser some shit like 56%. Both were massively overpowered on release, and Skarner in particular had to be hotfixed.
Then think back a bit more recently, and recall the buffs Xin Zhao was getting. People were touting it as the return of release Xin Zhao, and predicted he would be massively overpowered.
Then the patch hit and... well I mean, he was pretty strong, a bit too strong probably, but not overbearing.
Then recall people talking about how items like mortal reminder and shit were gonna gut a lot of tanks, and Mundo in particular. Then the patch hit live and Mundo was super fucking OP because of how strong the new tank masteries were.
Shit, I remember one idiot saying, without any irony, that once the marksman update hit live Miss Fortune would be able to beat Jax in a 1v1 late game. Needless to say this was not the case, and Vayne remains the only marksman that can even potentially duel a duelist like Jax.
Don't listen to the stupid ass motherfuckers on these boards when they're trying to predict how a change will affect game balance. Very rarely do they know what they're talking about.