Tron have their own witnesses. They don't need Steem witnesses. Stakeholders and community will go to the token which the exchanges support. Poloniex has already announce the token swap.
The other exchanges will likely follow, unless the current top witnesses can band together and appeal. If that happens, it's a battle of reputation between Tron - a $1.75b player in the crypto space - versus a bunch of randos they had no interaction with. Who do you think the smart money will support?
I haven’t thought of exchanges. Seems like a hostile takeover.