It is an old neologism, but the style feels surprisingly modern, and/or AAVE is so dominant today that even (youngish?) white people would have coined this type

It is an old neologism, but the style feels surprisingly modern, and/or AAVE is so dominant today that even (youngish?) white people would have coined this type of abbreviation today. > on June 19, 1866… "Jubilee Day" > The Black community began using the word Juneteenth for Jubilee Day early in the 1890s.