There is a New Age belief: “There is a coming splitting of timelines—one group of humanity will go towards ascension, the other remaining in the dark. Either “two Earths” will form or the “dark” portion of humanity will reincarnate into another dense world while Earth ascends.” What is Creator’s perspective?

There is a grain of truth here, that ascension is Creator’s ultimate plan for humanity, but this presumes the problem of evil being solved so there is no obstacle to ascension taking place. So the scenarios described here will not be taking place, either all will be saved or none will be saved. There will not be two Earths, either. If you go to a dark world, it will be the return to Earth in a new incarnation, assuming it is still here and the divine human experiment is still in progress and you have not yet been annihilated. Unfortunately, that is the plan for you and your world, that you will die out and then the Earth itself at some point in the future. This will be an active elimination, not a very slow degradation taking centuries or millennia; it is planned to happen within the next five years. So this schema of destiny being light or dark reflects the fact there is good and bad in play but it is not a useful description of how things will play out. That will be up to what humans do or do not do, and not to some larger force that is of a divine nature that sees to it. We can only do what humans request and at the present time, evil is largely being unopposed. There needs to be a human awakening to the problem of evil and the likelihood of these potential consequences, so people will take action to request divine assistance in healing the interlopers to enable a human survival and eventual ascension to a more glorious future.