This photo album shows the interior, that it is actually a Clipper Creek board with 240V-rated components. This video also shows the same board (and pretty much the same outer case) being used in “The Amazing-e”, a 16A 240V-only charger.I have meticulously explored the EVSE that came with my 2019 Bolt and nowhere on the unit, nor in the instructions does it say "capable of 240 V operation."
Where do you get the information that is is?
It seems likely that with some small changes, the Bolt's EVSE (possibly including a firmware flash and certainly new cables) can be turned into an Amazing-e.
But using the stock EVSE at 240V is off-label use and something owners do at their own risk. Most users who do so consider the risk minimal and likely lower than, say, buying a non-UL rated off-brand cheap 240V EVSE and using that.