Selecting ports for Availability Groups Listener and SQL Instances
According to this Microsoft Tech Community post, you can do any of the three port configurations you have listed.

You can choose the port numbers in many different ways.

Specify different port numbers for each instance and a different port number for the Listener.
Specify the same port number for all the instances (as a standard), and a different port number for the Listener.
Specify the same port number for all the instances as well as the Listener. This is possible because the IP address of the SQL Server instance is different from the IP address of the Listener.


It goes on to suggest the following as a possible best practice.


Don't turn on the SQL Browser service
Use the same non-default port number for SQL Server instances as well as for the Listener
Specify the port number whether connecting to a SQL Server instance, or connecting to the AG Listener

This practice may or may not work for all customers, but maintains consistency of the connection strings with or without the SQL Server Browser, with default or non-default port numbers, or whether connecting to the SQL Server instance or the AG Listener.