Is there supposed to a release of air from my intake (CAI cut down to an SRI) when I shut off the engine?

 

Yes.

 

when the engine is running, air is sucked in thru the SRI/CAI then thru the ThrottleBody into the CombustionCamber. when the engine closes the ThrottleBody & this creates a back flow out thru the SRI/CAI.

in other words, like M-Flo said, YES.