There is no clear answer on this so some parties have assumed the worst case scenario and others are open-minded. The only statements I have seen about converting STEEM to Tron is in context of Steemit and other dapps, which owner's have full rights to make their dapps work with any network. Statements have been made about Tron side-chain coins, presumably that would be linked to STEEM somehow to fulfill their purpose for these dapps.