Can CBDC be classified as cryptocurrencies?
If cryptocurrencies by definition are a digital currency that does not have any central authority to control/possess them, then CBDC is not a cryptocurrency.
If no what is CBDC running on? I mean what engine will CBDC runs on if not blockchain?
There is a difference between permissionless blockchain and permissioned blockchain. Obviously, the latter is very likely to be used by it.
Some are already saying CBDC is just like USDT what's true what's not?
Just by looking at the abbreviation of it, it is called central bank digital currency. USDT does not controlled by a central bank or any government, it just exists as an IOU by a centralized entity. It differs from CBDC who are fully controlled by the government and/or banks.