I was reading the ProxyAdmin contract and in this new release the transparent proxy deploys it's own admin,
my question is, if the admin contract will only administrate only one contract why the Upgrade and call function still requires the address of the proxy?
In OpenZeppelin Contracts 5.0, you are correct that the provided transparent proxy contract deploys its own admin. However, it is still possible to deploy custom transparent proxy contracts or the transparent proxy contract from 4.x, and using the ProxyAdmin contract from 5.0.
In other words, it is possible for a ProxyAdmin to be the admin of multiple transparent proxies, even though this is not the default behaviour.