Thanks for your feedback. I will copy this as a work-item and this way the prism team will be notified about this. Additionally, the community could vote the feature.
When you use Event Aggregator in Prism, the possibility of unsubscribing is meant to no longer handle an event from a particular component. It can be achieved by using the subscription token or the handler instead. For more information you
could take a look at the following documentation section on MSDN:
That said, your approach seems to be possible, but I’m not sure if implementing IDisposable will make this scenario achievable, since the subscriber has to indicate the EventAggregator instance from where it has to be unsubscribed.
Therefore, if the idea is to call a particular method for unsubscribing, you could create an extensions method which receives the event aggregator instance as parameter.
Regarding to Reactive Extensions, I’m not aware whether implementing IDisposable could help.
Please let me know if this helps.