To be honest, if RE6 ever does see the light of day again in the form of a remake, it will be redone from the ground up, story and all. I doubt Helena will even be in the game. If she is, she will be vastly different. Same with Piers.
That game just kinda tried to do way too much. Code Veronica needs some pacing fixes, but RE6 needs an actual reimagining. Something tells me that they will keep the Sherry and Jake aspect in tact, mostly. Leon, Ada and Chris will be incorporated a bit differently. I wouldn’t be surprised if Jill and Claire somehow end up being involved.