Sql-server – Change in microsoft documentation

Change Tracking and Change Data Capture are, while having similar goals, actually separate features. For AlwaysOn Availability groups, the limitations indicate that you can't use the synchronous Change Tracking feature at all, though the asynchronous Change Data Capture is possible to enable: It's just not a feature Microsoft will support for Active Secondaries.

Generally, things like that aren't supported because there exists a supported way to do so. In this case, enabling CDC on the primary node of an AlwaysOn Availability Group is completely supported, allowing the captured changes to be replicated along to the Active Secondaries, so would likely be the path you should explore for your SSIS needs on the secondaries.

You can read more about the differences between Change Tracking and Change Data Capture here, and more about setting up CDC on the primary replica here.

You have to set it up for all communication. If the WSFC is down, so is the AG and Listener. If you can directly access the secondary and it's set up, you can access it for readable.