So I just did a google search for double status and https://www.qantas.com/au/en/frequent-flyer/member-specials/double-status-credits-closed-members-oct19.html came up. So it seems there was a 1 week window and i missed it! But nowhere seems to have had it on the radar.
As the URL suggests it was a closed promotion - that is it was offered to a targetted set of members. By all accounts, it was a reasonably small set of members that received it.
Interestingly, though it says it was a closed promotion, it told me i was eligible for it, even though i never got the email invite, and it was also findable by google search.