I was wracking my brain the trying to figure out why my plugins were not being deployed as part of my solution between different tenants.
A closer look yielded the answer, that the plugin itself was being deployed but not the messages themselves.
To do this, you need to add in the SDK Processing Steps separately and then deploy your plugin.
Which really begs the question, when would you ever deploy an empty plugin assembly without the steps you already validated in a test tenant only to now deploy to Production?
A better solution to the above problem would be for the solution window to prompt you, asking if you want to add these already preconfigured messages to your solution (a la dependency components when adding entities).