Did you even read the post? Literally
We put some small buffs in for Talon himself, but also suspect his current power level is impacted by some of his must-buy items being a little on the weak side. We will be looking into buffs for core items that we think will help him out, and will continue to monitor him going forward.
And it's true. Lethality was kinda terrible, which screwed over most AD assassins. Now Lethality has been buffed, which should improve his performance by at least some amount.
If a champion is struggling you should look nearly exclusively at them, not jump into changing items, which affect many more champions than just the one struggling.
If a champion is struggling and many other champions that follow similar item builds are also struggling and you just did a massive shake-up on their core items, maybe it's worthwhile to look at both the champions and the items.