He did something similar back in the 1950s. This is how it's explained in his biography Midnight at the Barrelhouse: The Johnny Otis Story:
In those days if a white man was going to play music with black musicians, work in black clubs and stay in "coloured" motels it would be easier to pass himself off as black.
Sometimes it was temporary. When drummer Louie Bellson joined the Duke Ellington band in 1951 he was told "we're going down South so we're making you a Haitian."