Will a hypnic jerk need to wake you up to be classified as a hypnic jerk?

Not necessarily. No, a hypnic jerk does not necessarily need to wake you up to be called a hypnic jerk. It occurs at the transition of wake to sleep and people feel the "twitch" or "jump" and thus, wake up. For example, during a sleep study some people experience a hypnic jerk but to not wake up, although it is caught on the recording.