well there is no advantage to disconnecting the valve on a bike with a stock muffler. disconnecting is for aftermarket mufflers. or if you try a redneck diy mod such as manually overriding the valve to keep it open all the time. such at zipp striping it open, or safety wiring it open, or welding it open. The valve was originally meant for a combination of performance and EPA compliance, mostly the latter.
if you disconnect the valve cable, without overriding the valve you will do yourself no good.
if you do this mod just remove the cable but leave the controller plugged in or it will throw a code.
if you have a aftermarket muffler or plan on getting one this cable should just be zipped up out of the way.