“Any reference to the ‘Gulf of America’ initiative on your Google Maps platform must be exclusively limited to the marine area under US jurisdiction,” the letter read. “Any extension beyond that zone exceeds the authority of any national government or private entity..."
So the issue is not the renaming per se, but that waters previously known collectively among all countries bordering it as the Gulf of Mexico have been wholly renamed.
The argument seems sound: America has no authority over waters beyond its territories, and its territories end some miles off the US coast. Beyond that border it is only logical for a company to refer to a body of water by the name more commonly accepted internationally.