Locked users cannot receive emails from the system,Is this normal?


Is it Normal that Locked Out users cannot receive notifications?


Yes this is expected behaviour.
The logic is that a locked user may no longer work for the company and therefore should not be able to receive emails from the instance for data protection reasons.

It is possible to configure that inbound actions will process emails from locked out users. see: KB0744324
However you should consider the security implications of this carefully prior to implementing.