If a fake eviction was going to take place - ie the bedsit scenario, then the vote lines would have already opened and we would be voting who to put in there.
The only reason that the lines aren't open is because the people we are voting for are still unknown.
The "twist" is live. Therefore I am expecting some bull around them standing up and choosing one of their number to save and then replacing them with another. Due to the LIVE nature the whole shambles will be rushed. None of them would dare save Perez, so I could see someone like Alicia possibly being saved and then being replaced with someone else. I firmly believe that BB really want Katie Hopkins to win this show. Perez is good tv, but they want the whole "bitch turned good" journey blah blah. But given the other 3 up are not fans of Katie, she wouldn't get saved by them...so maybe they will let the whole house choose to save one of them. That would be the only way they could be sure she would be saved.