The developers stated that by 2028, when the game takes place, most of the main characters are either dead or have changed their lives.
Chris is the only one known to still be active thanks to Shadows of Rose.
Claire got involved in past incidents because TerraSave was targeted.
Leon has likely quit his job as Sherry is no longer leverage to keep him employed. Plus he was already close to having a mental breakdown during the Arias case.
Jill likely quit the BSAA as well, seeing that they were using bio weapons at the Village in 2021. Or, more darkly, she's dead from being used as a research subject.
Rebecca is still working on vaccines.
Jake is a mercenary, so he likely went out on his terms. But possibly he left children behind to ensure the antibodies could be used later.
Sherry likely resigned, having gotten tired of being experimented on by both her allies and enemies.
