I don't see why it wouldn't help, but expect a check engine light from the rear 02 sensors if you do this.
That said, SOLO exhaust offers their own high flow cats for the Camaro V6 and I don't see why it wouldn't be compatible with the 2012s. Its not cheap, but they are supposed to be able to be ran without causing a CEL....although a few people here have claimed the CEL did come on after lots of miles of driving (as in weeks to months of driving). I'm pretty sure there are recorded gains with these out there somewhere....maybe on their website?
Check out SOLO's website or give them a call.
Otherwise if you don't care about the CEL, I'm sure there are other options.
2016 Camaro 1SS - 8-speed - NPP - Black bowties
2010 Camaro 1LT V6 (Sold. I will miss her!)