Leon, Ziegfried, and Rebecca would probably be with the KC grand prix world found in the datamines. It was originally supposed to be before zexal, but konami switched it with dsod world. Depending on how long it takes to release zexal, you could be looking at a 1-2 year wait before they do kc grand prix before arc-v world is out.
Bonapart was just a npc character ID for the second gx chronicles and nothing has been leaked about grandpa coming to the game soon even though he is in the files as a playable character. Don't take rumors you hear seriously.
Leon, Ziegfried, and Rebecca can come with the KCGP world, but Noah and Rafael most likely will never happen, especially Rafael. He literally has no cards left to be used as drop or level up reward, all of them are already available in multiple boxes.
There's no real point in bothering Konami about Rebecca. We know KCGP's planned, and Rebecca, along with Zigfried, are clearly the two most likely characters. Judging by the leaked characters for DSoD, I'd hazard a guess that we'll even get Vivian Wong, as unimportant as she was. (Also Solomon Muto, which I'm cool with.)
B.I.T.C.H. please
B.I.T.C.H. please