you got that wrong my friend, if the miners switch to the new client, exchanges wont have any other choice but to follow, because the old chain will be dead..
Not really, because new miners can jump in and resurrect the old chain. There was a recent case of an altcoin, I don't remember which one, which tried to hard fork but couldn't because the one exchange it traded on stubbornly refused to go along.
That might be an issue for a small network, where one player may have the power to do so, but as Phil Potter from Bitfinex said, "we will see what our competitors are doing, if there is a consensus, we will follow it'
And that's why imo the fork won't happen. The majority of players like Finex don't mind either way *that* much. They just want to stay in business. Therefore there will be a lot of looking around and waiting for other people to make the move which is why it wont happen. As Gregory Maxwell has said, consensus is very hard to get in btc and there's good reason for it. It should be hard to make big changes to Bitcoin and the very large majority should be in favor of it to do so.