If you replace a central model on Revit Server, the model retains the same GUID. As a result, other models that link to the central model do not need to reload latest; they resolve the new version of the central model correctly.
A warning dialog displays when you try to save a model with the same name as one that already exists on Revit Server. You can choose to replace the model or cancel the operation. In Revit Server Administrator, a comment is added to indicate that the model has been replaced.
After a model has been replaced, if you attempt to perform any worksharing-related actions, such as sync with central or reload latest, you must first create a local copy of the central model before continuing.