"No need to remap" is quickly becoming the most misleading term in all of motorsports, and one that is used by way too many aftermarket can manufacturers.
I don't care which brand of exhaust you buy, if it doesn't have a cat - then you will be leaning out the bike (and the Scrambler is already WAY too lean already). I would never run an air-cooled motor in this condition, it causes too much heat - which will eventually lead to some kind of failure, somewhere down the line.
Besides, the bike will not perform anywhere near as well as it should - proper fueling fixes all that.