Possibly, but not necessarily (based only on the flight number). Fun fact, all flights (from commercial airlines) have a flight number, but those are not alway

Possibly, but not necessarily (based only on the flight number). Fun fact, all flights (from commercial airlines) have a flight number, but those are not always sold. They might be charters or ferry/repositioning flights. (And while it might make sense to sell a repositioning flight - sometimes it's done on short notice or the airline doesn't want to assign cabin crew to those flights)