Been a Falcon's season ticket holder for 10 years and have never thought the parking areas didn't have enough space for tailgating. We tailgate in the Gulch on the side near Five Points station. It's real convenient for my friends who take MARTA to games.
However, the city wants to build the multimodal station where the gulch is now so the parking situation will likely change. We'll see though.
You can tailgate at the game now fine but its not "tailgate friendly."
In the plans for the new stadium, they're talking patches of grass, bathrooms, trailer hookups, power, etc. The Falcons want to encourage a "collegiate" atmosphere at the game. Can only help us in the long run.