There's wax made specifically for matte paint, but not sure how a regular wax would be bad for matte paint. I'm guessing possibly giving an unwanted sheen.
This member waxed his frozen black
http://www.m3post.com/forums/showthread.php?t=619371
The after pictures are more of a shiny matte if that makes sense.
But yes matte paint for hiding swirls would be great.