Exactly, the old Steemit Inc stake doesn't really matter. If Tron has exchanges on their side, a majority of stakeholders are likely to jump ship to the new Steem on Tron. The swap on Poloniex sets an important precedent here. It's basically a $1.7 billion network versus a bunch of randos, the odds are heavily stacked in Tron's favour. Obviously, Tron will never agree to status quo, they want to recoup their investment, so a migration to Tron is inevitable. The best outcome for current witnesses will be negotiating a truce and a more gradual transition.
PS: For a Steem Classic, that's where they'll need to fork out Steemit Inc's stake, otherwise Tron could take control of both networks.