This is more of a bug report:
No option to hibernate/shutdown in GNOME 3?
text under the message says:
protected by Community♦ Oct 22 at 14:12
This question is protected to prevent "thanks!", "me too!", or spam answers by new users. To answer it, you must have earned more than 10 reputation on this site.
I currently have 32, which is >10. I can even edit the accepted response (that does not answer the full question) if so I wished.
So why can't I add another answer?
100%
for the entry and you have received a message at the top that said you gained the privilege.