I could see it being any one of the following:
-extra high-pressue version of 32 ACP mimicking the 38 ACP vs 38 super (if built on the 380 ACP version of the shield ez)
Would have to be sufficiently different to keep it out of .32 ACP guns.
-32 French reboot possibly with slightly longer/shorter case dimension just cause (if built on the 9mm version of the shield ez)
My thought, but as you say with proprietary massage.
-40 SW/357 Sig necked down to .30 or .32 caliber (mimicking the 40 super being a necked down 45 ACP)
Can't get 10 rounds of anything like that in a EZ. Even 9mm necked down (reinvent .30 Luger) would not increase capacity.