Most of that improvement is getting rid of TM. GM's not gonna reduce that. It's the limits they've designed in keep the autos alive for the 100k warranty period, not a lousy calibration. The only way that will change is if they can know for certain they aren't going to frag the tranny & drivetrain by raising it up. There is no upside to them doing that. The cars are performing to factory specs (barring the occasional low octane table issue). They risk losing money on warranty claims for something that most people don't care about. The people that care (us) about the issue are the same people that will cause them more warranty claims by using the extra performance and beating the car harder.
Plus, we are a minor segment of the market that will not go elsewhere and will just get new tunes. There's nothing for them to gain by changing that. They will only make tunes to address driving issues and bugs.
Nice to see that GMHTP is starting to crack into the 2010 SS's. What I think would be interesting to see is before/after runs on the rear wheel dynos in the lower gears (not for numbers per se) to show how much more is gained in 1st & 2nd (and on the shifts) by getting rid of the TM. TM is much more restrictive then. I remember on the GTO's that it yielded much larger gains in the lower gears.