With the latest update for SCCM Current Branch, the customization of the Software Center has been updated to provide a better administrator customization experience.
With this update, when you customize your Software Center you have an immediate preview of the change – you are not obliged anymore to deploy the customization to test it
You can also showing/hiding unapproved application and/or installed applications in the Software Center.
By default, installed application are now hidden in the Software Center. Which means with this default settings, you can only view installed application from the Installation Status tab (if not hidden by the customization).