Apparently this is similar to the "German Vote" urban legend

The US does not have an official language and such a vote has never been held. According to the article above "...Congress considered a proposal, not to give German any official status, but merely to print the federal laws in German as well as English". Also "...in the 18th century there were rumors that a few Brit-bashing superpatriots campaigned to have the new nation drop English in favor of Hebrew, French, or Greek...".

So it turns out that the 'Greek' reference in this German urban myth created another all new urban myth commonly believed in Greece. I have heard lots of people talk about it as if it were an undeniable fact: professors, authors, even my teacher in my elementary school in Greece. But we can safely say that the survival of this absolutely false story can be attributed merely to the ever prevailing Greek chauvinism.