What fluid you use is up to you but the reason I can recommend the fluids above is that it came from ZF the manufacturer of your transmission not repeat not a provider of ATF that says it is OK. Let me ask this if your transmission fails who do you blame?
Dropping the pan and refilling it with the saved fluid is not a good idea if your transmission has 50K miles or more.
I have never heard of any transmission failure from dropping the pan and refilling to the correct level with the RIGHT ATF. I have heard of and experienced transmission failure from flushing a transmission not from refilling one.
Unless you have over 120K miles on your transmission there is no need to replace the pan/ filter.
You are not saving any time or money trying to leave the pan in place.
Risking a transmission because you are trying to use an ATF that the manufacturer states is compatable isn't for me.
All of this assumes you have the GA6HP19Z (ZF) not the GA6L45 (GM) transmission..