The node operating as the (AG),PRIMARY will be the node that the LISTENER will connect to.
Just to be clear NODE A and Node B are set up as an FCI with Node B being Passive.
Node C is the secondary replica of the Instance running on either NODE A or Node B.
The answer to your questions is YES.
If SQL SERVER Is either running on the Primary Node A or Node B. Then the listener can be used.
If the AG is failed over to NODE C. Then the LISTENER can still be used.
Ok, so something is wrong with my configuration because I can not connect through my listener when failover is performed manually from node_a to node_b
Here you can see my problem https://youtu.be/r5A5f5NtW1Y
In the minute 02:10 I move my FCI from node_a to node_b