Presumably new exchanges would spring up to fill the vacuum, as a lack of exchanges would create a market opportunity.
The price would probably respond to the impetus behind the exchanges' disappearance, rather than the disappearance itself.
There are so many great exchanges right now that are not coming up because of the hype of binance and some of these other great exchanges, so if there is no binance and others, it would just be a chance for those exchanges to lift their head up and for them to be known in the industry.
Binance, poloenix, bittrex and others may be the best and most popular now, but it doesnt not mean that there are no other exchanges that cannot be the best too because they have very solid team and very promising future, but the hype of other big exchanges would not allow them to really thrive that much in the market as they are not able to compete with these bigger ones and not able to woe some of the clients that have packed to themselves.