Why not both? The new film could easily be a strong, standalone story that doesn't contradict the original continuity.
The original continuity is filled with contradictions, though. There's no way for Taylor to go back in time during the first movie, but that was ret-conned by the second movie. There's very little time for Cornelius and Zira to get to Taylor's capsule between the last time we see them and the end of the world in the second movie, let alone to repair it--remember that this is a culture that doesn't even have airplanes. Yet somehow they manage to repair the craft, launch it, and successfully travel back in time. And when they travel back in time, they arrive in 1973. Which is exactly the same as 1973 except for the rather fantastical spacecraft of Taylor's, which apparently was launched previously to the events of the movie.
Nah, the original played pretty fast and loose with the continuity. No reason this one can't do the same.