we know that the french guy is not a former one. he says himself, "Listen up boy, I have survived your predacessors and I will survive you as well."
did he survive himself? of course not. He is a traffiker of information. Persephone wants to feel loved again like she used to. That's why she goes around asking for a kiss from everyone she meets, including Ghost and Niobe. (great scenes from the game)
Saraph might be a former one, but I severely doubt it. As far as we know, all 5 previous ones have been taken to the source where their code that makes them "the one" has been deleted (no humans actually carry and code, but whatever part of their mind that lets them do the wacky things they do, when plugged into the matrix, converted into code is removed), and they are lead to be free in Zion with 23 others.
They are known to be the "first" person to escape the matrix. Morpheus refers to the "first" as well. When Neo discovers that he is in fact that sixth, he says himself, "Either no one knows, or no one told him."
The people who knew (Oracle, french dude, persephone) didn't tell him. (french guy hinted at it, but didn't blatantly say it)
Morpheus, Trinity and all others part of Zion didn't know, which leads me to believe that the former "one" did not know as well, otherwise they would all know that the cycle has been repeating. Neo is the first to know of this cycle.