There was a definite "Go" signal given by Al Zawahiri on Oct.1
IMHO, the signal was also meant for the cells that will attack us here at home before the election.
I think the "GO" codes were given months ago. But it wouldn't surprise me if this was a "spare" as we used to designate it in the infantry to give a sort of prearranged signal questioning: WHY HAVE YOU NOT MOVED? sort of thing. IOW, another "go code" meant to reinforce???? More like GO, NOW!!!