It can be if that's all the rider has in the tank. I've placed inside the top 10 in races via a 70 rpm sprint while I had a bad cold, was tired, whatever. My sub-1000w sprint was at low rpm too, although I don't know the cadence offhand.

When you sprint at the end of a race, by definition it's a sprint. It's like asking if a bike is a race bike. If it's ever been raced, it's a race bike. A SRAM Red Pinarello that's never been raced is not a race bike.

HOW you do a sprint is different. There are different techniques for sprinting and a more efficient technique will get you a more effective sprint. "More effective" could mean more stable (i.e. you get bumped but it doesn't faze you, versus you get bumped and you crash), allow shifting while sprinting (which allows you to stay in the meat of the power band), use more muscles or muscle groups, position you for a better bike throw, etc.