I am replacing my garbage disposal and ran into a question I can't seem to answer easily. I currently have a 50/50 split sink, one side with a disposal (which quit working and started leaking). I got a new insinkerator evolution, 3/4hp to replace the badger 5, 1/2hp. The dishwasher is currently connected to the NON-disposal side of the sink via a wye connection affixed in the horizontal before the P-trap (which I believe is up to UPC--I'm in Kansas, if that helps).
Is it preferential to relocate the dishwasher drain to the disposal? if so do I need an air gap? Or does the disposal function as an air gap? I've read about the air gap but it seems like every other thing I see says "if no disposal you need an air gap" or "if using a disposal you need an airgap", but not the other way around (contradictory information). I do not have an airgap in my current arrangement.

Thanks,
Matt