If you are lucky someone posts a thread here in this forum. However most of the times we are left out on when and how long Oracle or Jive is working on the forum. If you get an screen telling you that the forum is not available, you know. Changes to the underlying software are a different story. They are deployed at some point in time and we, the users, may notice a change in behavior. Then we guess that there has been an update to the software and we post what we have noticed here. Then we may get a confirmation from Oracle.
You may want to check in MOS as they sometimes post outages there.