i prefer Rebecca Chambers to come back and specially Barry Burton. I haven't read what happened to them. I stop playing RE since 4 and i was able to play this game because my friend has it and doesn't want to touch it anymore lol.
copy ninja Kakashi has copied a thousand jutsu and i'm going to use them to their fullest Extent! - Kakashi Sensei Ep 266
Claire is a passive civilian. She does peace protests, not military or government operations. She was only involved in the first place because she was trying to find Chris. She can handle herself if dropped into a situation, but is VERY unlikely to actively go out into the field again.
Rebecca either died in Raccoon City, like Brad Vickers, or probably went on to become a doctor.