Probably more accurate to write that the changer control is not present in many of the current head units, not necessarily most, and it may be more the case with European models than U.S. (btw, it's also much easier to tell on the European website). Europe still does not have an equivalent to Sirius, so no consideration is made on the head units for sat tuners. The only option are digital TV tuners, which connect via a different interface. Some of the multimedia head units have the right connector, but it's designated for nav input, and the manuals do not make any reference to changers.
Anyway, the one you posted clearly has the changer control -- as long it says it has the changer control, it's the one you need for the KCA-S220A switch.
What I still do not understand is how adding a 2 into 1 switch to a changer controller that seemingly lacks the protocol for controlling the Music Keg is going to remedy the situation. Though that switch model is several years old and would be compatible by itself, it's still a slave to the master controller.
If you get confirmation from Kenwood, still make sure you can return whatever you get in case it doesn't work out. I will certainly be interested in the results, because I would like to be able to change my head unit at some point, but not if it means giving up my Keg.
