According to some older posts I've read, Some or all of these came with Sonar 8.5 but most of the issues started around x2 or x3. Maybe during install it sees an issue and disables them. Or, as scook says, they're in the background fueling Style Dials, or something.
I enabled them and the VX-64 seems to work just fine. Not sure if I'd ever use these so I'm not too worried if they work or not.