Is this language significant for any reason other than sharing a name with Google's new language?
Signed, an obscure language writer
So why again should Google make the name change?
If the 'Go!' creators had any hope for using that name on a series of offerings (tools, books, etc.), they have to object to Google's use, to retain the presumptive rights they'd established so far via use.
Notably, the word 'bang' does not appear in the book, "Let's Go!", so it is unlikely to be the author's preferred pronunciation: