I think the reason they have done this is that they know they have put in some relationships that will not last the full filming process, that they are doomed to fail from the start, so the producers are aware (and indeed plan) for new people to fill the gaps left by the ones that won’t last the difference, they know full well that there won’t be 12 couples at the final commitment ceremony.
As for the whole Ella debate, she pisses me off sitting there with her fake tits hanging out claiming to know what it feels to be a woman, no love you don’t, cos if you did you would have grown up with crappy attention from predator men as your body develops and you would not expose yourself like that because you would be frightened about what reaction you would provoke and even worried about being attacked