No. A Power of Attorney (PoA) is not equivalent to a joint account. It provides access rights to someone else's account but does not establish full ownership. The main account holder remains the sole legal owner of the assets and main recipient of all communications.
In addition, PoAs can vary significantly in scope: some allow only limited view-only access, while others permit trading or broader operational rights. However, even the most extensive PoA does not confer the legal status of an account holder, and the PoA can be revoked by the main account holder at any time.
The new joint accounts require two fully identified and onboarded account holders, each with their own personal accounts and credentials, and both becoming full owners with equal rights and responsibilities.