Exactly. I'd feel pretty pissed off if I was any of the girls, and honestly considering the controversy from last year it's a risky move, but maybe better than him dumping the final girl for a random, at least they can maintain their lasting relationship track record.
It would explain why Lana is so smug all the time.
If I was in Lana's position I would not agree to go on the show, but that's just me, maybe she wants a media career?
I remember in 2006 there was a show Yasmin's Getting Married which I think only lasted one or two eps, but shortly before airing it had been Renee instead of Yasmin but Renee met someone else independently and dated him. Anyway, that's probably my quota for remembering stupid trivia about dating shows for the day.