andrew wees is correct. I searched my program guide and none of the channels you listed broadcast in HD. i don't know why. Are these channels of music videos? Do they still make music videos? The "big" music channels (MTV, VH1, CMT) are HD but I didn't see any programs with music videos.
When music videos were popular, production companies only formatted for TV in the NTSC format.
You heard "COX Phoenix carries NO SD Channels" is obviously untrue. There are lots of SD channels. Andrew is probably correct you heard Cox Phoenix carries no analog channels.
However, if these SD channels had analog modulation, they'd probably not be blurry. Just my thoughts.