VS951 -lgw to las 6th Oct 2016

Currently have a holding booking for a couple of PE reward seats on a flight VS951. Initially it took the operator by suprise as wasn't aware of such a flight. He spoke to his support team who confirmed that the flight was valid and bookable. I'm slightly concerned that there appears to be no history of previous flights for this flight number. Would virgin really schedule a one off flight? Should I be concerned that the booking will probably be cancelled due to some sort of error? Would welcome your thoughts. Thanks.