I am not sure if this is what you are talking about, or if the Corvette has it, but some other GM cars have what is called "Performance Algorithm Liftfoot" (PAL) which helps determine what the automatic does after you lift your foot off the accelerator after some earlier heavy acceleration.
The idea is that you don't want the car to shift up gears (enter lower torque band) when you are going to need to get back on the gas hard in a few seconds anyway. For example, if you are driving on a curvy road and have to lift your foot for a curve, if the car allowed the gears to shift up under the reduced load, then it would be in the wrong gear (too high gear, with too little torque) when you got on it again a few seconds later after you got out of the curve.
If that is what your Corvette is doing (holding a low gear/keep RPMs and torque high for several [approximately 5+] seconds after you let off the gas pedal), then I personally would consider this normal based on knowing GM's history on this in other cars.
Does anyone on here know for sure that Corvette uses PAL like what is done in some other GM cars' transmissions' programming?