Hey, congrats on the new car
The second gen MCS
should pop and burble just fine, both my hatches did and my coupe does like a boss !
There was a period of time that people reported it was being coded out of the ecu, however this was reverted back as people complained about it. It could be possible that this is the case for yours, not sure how you would check without going to the dealership.
It could also be a lot of carbon build up that is preventing it from popping and banging. Have you taken it for a spin to get it very very hot ? Also try using Shell V power ( a lot of people comment that this jungle juice works a treat for noise ! ). You should be able to play with the accelerator once nice and hot.