No, that's still one flight path just with several stops. So there's not more than one plane in the air with the same number. There's a difference between a flight "continuing on" and an entirely different flight plan. And I dunno, there's probably some percentage of riders who might continue on past a single stop. It's not impossible.

For example:

https://www.southwest.com/air/flight-status/path.html?depart...

There won't also be a SW981 today that say takes off from HOU to OKC.