Received a Ghost update on Dec 12

Hi ALL, is there anyone who can reply?

I Submitted AOR on Sept.5.2019 Passed Medical Exam on Sept 19. 2019

After that, there were no changes at all.

Last week on Dec.12 2019 I saw there was a ghost update in my account.

Does this mean that PPR is coming soon? or Could it mean that there is other process going on such as Security Screening or Review Required?