we have Node.reset_to_discover call in stop_deployment_resp method of nailgun/rpc/receiver.py code. When astute sends the report for stop deployment, it sends these nodes in rpc message body. And this method marks nodes as 'discover' and pending_addition. That's why provision graph picks them for reprovisioning.
Okay, the RC is different:
we have Node.reset_ to_discover call in stop_deployment _resp method of nailgun/ rpc/receiver. py code. When astute sends the report for stop deployment, it sends these nodes in rpc message body. And this method marks nodes as 'discover' and pending_addition. That's why provision graph picks them for reprovisioning.