Not sure where you guys are getting the idea that the Twitch delay is to prevent ghosting, sure you can't ghost exact positions but you're still going to be able to ghost Ward placements, Dragons, barons, jungle paths, etc. Even before the twitch delay popular streamers would stream with no delay because it helped them interact with their viewers easier.
Twitch has a delay because they changed how their hardware handles streaming. The new increases server stability, which no change to the physical hardware, at the cost of the delay. --- # of STP's-6