Are there quiet discussions among the Anunnaki of having to sooner or later (and perhaps sooner) abandon Nibiru altogether and commandeer Earth as their new long-term home? Which is why they are seriously debating the future utility and desirably (or lack thereof) of keeping humanity around?

They do covet the earth but more as a possession rather than a destiny. They do not desire to live on earth because it serves them to have their world and its current orbit, even though it causes problems as well. There are other worlds they interact with and they are not willing to give that up. Their nomadic lifestyle, even though space-based, is so great a part of their culture they would not consider the immobility on a small planet like Earth as their only habitat. So the desire to have the earth for their own use is simply to have an outpost to use for selfish reasons, much as one might have a second home in a warmer climate for vacations.