With Outlook open or closed, the Lync client does not update the presence information based on meetings in the Exchange Calendar. I checked the OAUTH configuration and it seems to be correct, but my understanding is that this should default back to the Outlook integration as a fallback so this should still work. I can reproduce the issue at two different Lync Server environments, and on both pools at one customer site.
Both Servers are on Lync 2013 CU6, and all updates are applied to the client. Of course, the Lync client is set to automatically update its status in settings.