I have a Huawei WS319 router. The admin password is known to me and my friend.
Is there any way to learn WiFi password (through automatic notification) if it gets changed in the future, given that I have full access as admin?
You'll need to find a secure channel to exchange the new password over. Communicating verbally would work just fine. As to an automatic notification, the only way to do this would be to flash your router with custom firmware which would allow you to write scripts to add functionality, such as DD-WRT. However, DD-WRT is unsupported on the Huawei WS319. As always, flashing the firmware on the router runs the risk of bricking it, so ensure that the firmware is compatible before flashing it.