Yes, as long as the rep has the permissions to change the Status within SFDC.
You can build a trigger campaign using the "Progression Status is Changed" trigger. Select the program that has been synced with SFDC and add the constraint "New Value". Enter "Registered" there. Then, in the flow steps, "Send Email" and reference the confirmation email you have/or will be creating.
I would also recommend doing this for the Leads the reps change to "Rejected." You can do it all within the same campaign. Add the same trigger as before, but change the "New Value" constraint to Rejected. Then, in the flow steps, "Add Choice" and reference the "Progression Status" filter. If "Progression Status" is "Rejected", send a sorry email. Default can be the thank you for signing up email.