ItemRenderer is designed to be primarily used in MXML. Because of that we support states.
However, MobileIconItemRenderer is primarily used in ActionScript. Because of that, we don't see a huge reason to support states. If you want to know whether you are selected or not, look at the selected property. Same with down.
The only reason I can think of to support states would be to allow AdvancedCSS styling.
Is there another reason you have for wanting states?
If you file an enhancement request with your use-case, it's something we'll consider, but we'll have to weight it against the perfromance cost associated with states.