I believe Voyager must have somehow been part of the phenomenon, a third "pole" or something that caused time to pass at that rate on the planet only while they were in orbit (or it would have been just too coincidental that Voyager orbited the planet just exactly during the brief time it would have taken them to pass through those stages familiar to us). Thus, I figure that once Voyager escaped orbit, the phenomenon abated, an idea I feel is supported by the final shot of the episode.
But if the phenomenon continued, where would they be in a few years? Wow, well, the chance remained that the core could have been unstable, or that they could have destroyed themselves through environmental abuse or a war or something. But if that didn't happen, heck, they would have been on the fast track to ending up similar to the Organians or the Q. If they wanted to explore the universe along the way, though, maybe they'd have wanted to use their advanced capabilities to match the passage of time to the outside universe themselves; otherwise, they could probably only "explore" by bringing others to see them, like the Cytherians did (but even less convenient for those brought).