Hello Casey,
You could also use the "Program Status is Changed" trigger with the "New Program Status is" Add Constraint. Your flow would then send the confirmation email.
Also, make sure your Roadshow Event in Marketo is scheduled (Event>Event Actions>Schedule) to occur on the same day as the actual event. It won't show up in the Marketo app unless you are are within a week of the event time scheduled in Marketo.
-J
Justin is right--use the status update. I'd recommend a batched smart campaign waiting for the status.
Hey Casey, I moved your question to Products & Support for more visibility.