As a Talon main I can't say that's fully true. Early game you're pretty much going to famine, unless you're up against a bad Azir. In a match with a good Azir, you won't get any cs without using Rake or getting hit by an auto or two, maybe even a Q.
By Mid Game it's about the same. If you can't farm you can't 0-100 him fast enough to survive you're not going to win. So being starved of CS now you have to roam, and he'll probably push and take tower, or worse, follow you.
The only real way you win against Azir as Talon is if you're so skilled, and build purely around him, that you can dodge all his Q harass, and E Q W him as a harassing mechanism a few times before going all in. Trouble is, a good Azir will typically keep a sand soldier up just in case you get too froggy, and he'll easily out damage you since he can slow you. There really is no winning against Azir as Talon unless he does bad or you can get a good gank.
By lv. 6 his ult guarantees you won't kill him. The moment you E he'll probably Ult you, or if his twitch mechanics are on point, Q away, ult you under his tower, and kill you. It's really only a matter of if you can kill him faster than his Ult can go off, or he can react to you. And without a Silence anymore, this is pretty difficult.