By "Castlevania ReBirth", I mean a new game in the "ReBirth" series of Konami WiiWare games, this one would be a Castlevania game (like the Gradius ReBirth and Contra ReBirth games). So, it would be a new game done in the old style and probably not a remake of an older game. They could always make a new Chronicles game for WiiWare based on an older game, but I doubt a game would be branded as both a Rebirth title and a Chronicles title.
I'm not sure if we really need a WiiWare Chronicles game though, since they can just release old games on the Virtual Console in their original form and charge almost as much. They could always do something like make a "Dracula's Curse Chronicles" with updated graphics for WiiWare, but it wouldn't be like the Chronicles games we have, which tend to contain both the original and arranged versions of the game, considering Dracula's Curse is already on the Virtual Console. Chronicles games have been used as excuses to release older games that we never made it outside Japan. Vampire Killer and Haunted Castle are the only ones that we still need (unless we own an old arcade machine or old computer), and it'd be much easier now just to release them via the Virtual Console.
I should go and get both ReBirth games just to support the series in hopes that they make a Castlevania one.