TRON and Steemit’s development teams will immediately begin working together to bring Steemit and other Steem blockchain based DApps to TRON blockchain

old STEEM token to a new TRON based STEEM token, giveaways to the existing TRX users with the new TRON based STEEM token

It seems pretty clear Tron plans to abandon the existing Steem chain and move everything over to Tron, timing unspecified. Witnesses can't do anything about it as Steem witnesses have zero control over the Tron blockchain. Furthermore, Tron has already initiated a token swap on Poloniex, and other exchanges are likely to follow. Once swapped to TRC STEEM, current Steem witnesses will lose all control.

Of course, current witnesses can continue the current chain as Steem Classic or whatever, but Tron's future of Steem is pretty clear now.

Excuse the plug, but some discussions about this here: https://steemit.com/steem/@liberosist/steem-classic-anyone