Sony has announced that the PS4 will now support up to 4 primary user profiles, meaning that you can switch between your regular profile, a profile for a friend, and a profile for a child. This means that you no longer have to worry about having to create multiple profiles just so that your family can all play games together. This new feature was first introduced in the PS4 Pro, but it is now available on all models of the PS4. It is also worth noting that this feature is not exclusive to the PS4 Pro; any PS4 model can now support 4 primary user profiles. This new feature is great news for those who want to be able to share games with their family without having to create multiple profiles or worry about them playing different games. It also makes it easier for friends who want to join in on multiplayer games without having to create a new account or password. ..
They’ll never tell us but what happens when they do merge/split is both accounts are put into a state similar to suspended users when logged into the PS4. All content is still accessible and you’re able to download anything from the cloud onto the console, but essentially both accounts would be removed from being primary at that point: which means saved games would no longer have access to online services (trophy lists, game updates, etc). And once you log out, whichever one was chosen beforehand as your new primary account will become the only one thereafter.