Each DApp will have their own decision to make and they might get some funding thrown at them by the Tron Foundation / Steemit partnership to help with the decision. However, considering the impending SMTs and the fact that TRON has it's own smart contract / tokens I don't see Steem Engine being that viable on TRON. DLease will probably depend on whether SP delegation functionality moves over to TRON and it might be one DApp that could more easily support 2 blockchains.