Correct. They are in the business of removing and replacing the input cord, and would like to protect that business. In addition, as you point out, they are discussing a circa 2011 Nissan EVSE, which I have not seen the internals of.
We do know what the internals are for the 2017 and 2018 GM Volt / Bolt included EVSE. Pictures shown here. (Potentially 2019 too, but I have not yet seen verification of the same GM part number EVSE )http://imgur.com/a/vFkP5
From the pictures, and the great work done by this individual, we can conclude:
1) GM sourced the PCB from Clippercreek
2) GM desired a single part number PCB that could be sold worldwide and used from 90-265VAC.
3) The input components are rated for "high line" AC (Up to 265VAC)
4) Many folks have made or purchased "pigtail" adapters and are currently using them.
Although removing the cord and replacing it is an option, I am not crazy about that as there is no indication they use a thermal sensor in the new cord to detect overheating, caused by a bad connection. The best solution would have been for GM to have put a 220V plug on the included EVSE and also included a 120V plug adapter, IMHO.https://gm-volt.com/forum/showthread.ph ... on-Capable