When Ethereum finally becomes the biggest blockchain by market cap 0xBTC will become the BTC emulation that is used as a deflationary store of value on that blockchain.
Bitcoin will die and cease to be a blockchain of any importance and people will switch to investing in 0xBTC which is compatible with the Ethereum network.
Time will tell. Let see whether 0xBTC will be able to keep itself alive or not. No need to compare it with bitcoin for now. There are still many good alts that already proven by time which is better for investment.