Yes, many people will likely try to sell off their Segwit2x coins and drive the price down from where we see the current futures price. I don't think it will go that low so quickly though. Since there is no replay protection, I can see many people holding on to theirs out of fear of losing their bitcoin and will wait for the dust to settle before selling.
The initial low price of the 2x coin could be a good time to accumulate.