While the discussion over change node having ability to delete whole msg properties continues..
I'm wondering if (as probably simple to implement, without side effects and be very explicit) the trigger node could have "new msg object" (or some other description) as one of its outputs?
If this was introduced first, we could use it in front of a change node and then see if we need it integrating into the change node or a more nuanced version in the change node
I would go beyond creating an empty message and also propose to have the node accept a JSON string defining the entire "Send" or "then send" message. I frequently send pairs of messages, the first forcing a system into a known state and the second triggering some action. The trigger node has worked for me here, as long as I only have to change the payload. (BTW, the node seems well-behaved in preserving all the other properties of the incoming message, although I haven't found this documented anywhere.)