Being that any semi-definitive information regarding MY07 93 EHU swaps is hard to come by, at least for me it was, I want to share what I now know from my local shop:
NOTE: This is for MY07 (2007) interior redesign and audio overhaul 93s
BOTTOMLINE: IT IS 100% POSSIBLE TO SWAP EHUS THAT HAVE NOT BEEN DIVORCED PROPERLY
-If the donor EHU was not divorced, there is no easy way to swap VINs as many articles discuss about MY06 and older 93s and almost certainly not via a TechII.
-Swapping VINs COULD be possible via an emulator but my shop has never had success doing so when they've tinkered around on their own cars.
-EASIEST GUARANTEED SOLUTION
If the shop has access to GM security codes (paid shop subscription if not designated GM service center), that is all they need + a TechII.
10 mins the shop was able to swap out my headunits. Cool fact but not cool as I dont need two, but once an EHU is programmed to a cars VIN, you can plug-n-play any number of them without having to reprogram each time.