Take into account that your scenario is not taking advantage of modular application development proposed by Prism. You should separate your functionality into modules in order to make your application architecture flexible and maintainable. Each of these
pieces encapsulates specific functionality, and is integrated through clear but loosely coupled communication channels.
On the other hand, as Prism documentation shows “Module instance lifetime is short-lived by default. After the Initialize method is called during the loading process, the reference to the module instance is released. If you do not establish a strong
reference chain to the module instance, it will be garbage collected.
This behavior may be problematic to debug if you subscribe to events that hold a weak reference to your module, because your module just "disappears" when the garbage collector runs.”
One possible way to fulfill your requirement is to use Event Aggregator mechanism, by publishing an event on in the
LoadModuleCompleted handler and subscribing to that event in your module, for example to register something in your container.
You can read about these topics in the following links:
I hope you find this information useful.