Central is not relative, central Atlanta means central Atlanta. Local is what you are talking about (or Central to Forged). Local would be what is close to the group in Marietta, etc.
That being said, if mostly everyone lives in Marietta and that area and the meet is there, the non-local people who dont want to be in traffic forever probably wont come. I've been up I-75 numerous times on weekdays and it isnt worth it for any car meet honestly. I'd rather meet up somewhere where everybody drives a little to get there.
(Refer to my previous comment about enjoying the drive in my car, assuming its not in dead stop traffic)
Besides, the meets off Barrett at the Starbucks are a joke
. If that is the idea about the monthly meet is to drive up I-75 in traffic and then head on to a Starbucks near there, I'll save my gas.