Again, this is a quarterback doing a better job. Ultimately it comes down to the receiver beating his man and the good quarterbacks don't have some magic wand that just magically makes the receiver able to generate separation.
In the first quarter last week, Wallace beat his guy on a post for tat long gain. It was a great throw, but obviously would not have been a successful play had Wallace not beaten his guy. Flacco wasn't involved in the route before he threw it, so he had no impact on the route itself (Wallace beating Skrine).
If it were true that quarterbacks make players better, then the Patriots would not spend early picks on pass catchers (Gronk, Dobson, and others in the 2nd/3rd round that did not pan out).
It's the same issue that we have seen with the Ravens. I'm sure most of us can agree that Flacco is at his best when throwing downfield. The line has been brutal this year and he does not have the time for the deep routes to develop. Does he magically become a good down field thrower again if he is able to, ignoring the bad footwork, step up and throw the ball deep?