This is one of the dialogue responses with Paarthurnax, when he points out how this world could be the egg of the next kalpa. So if the World-Eater is banished, could this lead to the next world falling onto Nirn since Alduin couldn't clean up Tamriel? Or perhaps, by "take care of itself," it must forcefully integrate itself onto Tamriel through an invasion from across the ocean in order to exist. Perhaps the tiger dragon emperor will make Landfall soon once he mantles Alduin.