i kinda doubt it - there's photos on their site of them using a cutting wheel to do the metal edge... a waterjet would go right thru that right?
i think its mostly machine shops that have waterjets as apposed to snowboard shops
i've talked to dudes about getting the waterjet cut and most are charging $40-60 and this whole class is 50 bucks. i also think part of the whole point of the class is to learn how to do it yourself for future use as well....
.... if i was gonna diy a board i'd get it waterjetted but that's because i have ocd
for most people i don't think its the end of the world, especially if its your first split. a nice straight cut is probably good enough.