I just realized that the Force Awakens essentially “retconned” (does that mean written out of canon?) the PT. The PT made clear that Vader was destined to destroy the Sith based on some ancient prophecy, and I’m assuming that Kylo Ren and that fish guy in the hologram are Sith - or at least the equivalent. So basically all that nonsense about the space prophecy and Vader being the savior of the universe was irrelevant.
The Sith are one of many organizations that uses the dark side. The Nightsisters in TCW aren’t Sith and neither is Kylo Ren and his master. Abrams mentioned that Kylo Ren isn’t a Sith. Therefore, the prophecy is irrelevant to TFA. It never said “destroy the dark side.”