there is no "what if" in what you are asking. shorting have always been happening during each drop for years. in fact i do believe that a big reason why the drops happen and all the FUD is being spread to intensify the drop, is because so many people are shorting bitcoin, big players or small fishes alike.
Will bitcoin futures change the meta?
no because the way these futures work is that they will close down trading and all positions if price is dropped more than 7% which means they should have closed it back at $18,289.38 when the first drop happened.