With the Season 4 update they brought back solo Rebirth and a new Rebirth program but with a twist. Communal Rebirth where not only do you have to complete the trial but you also have to find 3 frequency machines and up to 4 evidence boxes (this depends on how many players are in your lobby) BUT everything is backwards as well so brush up on your memory skills and remember the map layouts. They also added new "endings" if you even call them that in the form of newspaper articles on tragedies that are occurring around the globe as a result of your "training."