What is token swap and how its works
The dev will create a new contract and will replicate the eBTC balances to the new one. So you'll end up having eBTC on both contracts, however your eBTC on the old contract will be worthless.
i transferred all my token into new account , do i receive new ebtc token on that new account
You don't worry about it. They will announce method of swaps when it happens. Only need to keep ebtc and your private key of the wallet. It's good to see a new contract.