What you are trying to do might be possible, but there would be no way to block the default behavior of CloudPages. Have you considered using OpenDirect if you do not need the inbox?
Also, 2 things: 1) You can't get to the CloudPage data from the event you're mentioning and 2) the EventBus may not be around for many more releases of the SDK.
- You can't get to the CloudPage data from the event you're mentioning.
- The EventBus may not be around for many more releases of the SDK.