Both the 3800 Series 1 and the 3800 Series 2 supercharged motors I've driven have this feature. It's not just a feature to save power when you need to accelerate, but also to save the compressor. I don't suspect the compressor likes spinning at whatever the pulley-adjusted speed is when the engine turns over 5000+rpm.As far as I know, no 6 cylinder engines have the A/C shut off when during hard acceleration. This feature appears to only be on 4 cylinder engines. Many 6's are just barely powerful enough for the vehicle size, so the A/C drag is really noticable.
As an aside, my Fiero 2M4 had the A/C cutoff feature in 1985.