Alright, so I went to the open call in Atlanta and while I did not get a call back, I can share a tidbit that makes me think this secret thing may have some validity.
In my group of 5, there was a girl, a blonde model from Atlanta and she mentioned something like "I am dating 2 guys - one knows and the other doesn't know" after she said this one of the casting people stopped her and said "don't tell the rest of what the other guy doesn't know in front of everyone else". After we were all dismissed, she was asked too stay behind.
There was a gay guy in my group who I walked out with and I wondered aloud what was up with her and what was the big secret. The gay guy told me she was a tranny - a friend of his knew her and he told her to come to the open call.
She mentioned she had never seen the show, knew nothing about it all, and just because of her "secret" I am 99% positive she got a call back and would not be surprised to see her on the show. She was really pretty but I HATE HATE HATE that another know nothing about the game dumb bitch may be getting on because she has some sort of overexaggerated "secret". Even though I would LOVE LOVE LOVE to blow her spot up - I won't mention her name - I can PM it to Aero or SoA and when we know they are sequestered I will post it. Again, she may not be on - but they made a big deal of her not spilling her "secret" in front of the rest of us and y'all KNOW a beautiful blonde tranny from the South who grew up on a farm and knows nothing about BB is the kind of shit these dumb casting idiots drool over.
They did ask all of us if we had something interesting to tell them about ourselves "that no one knows about." So, having been through the casting and hearing other people's stories - I am inclined to believe there is something to this.