I would say element six might unlock last during next week’s extraction event.
@Jupiter.blues below, I’ve always had the impression a trailer would be the last reward, just before launch. Since release, HG have only released trailers on the day of an update or as with last Summers ARG, we received an in game photo and then received a trailer shortly after, possibly on the day or night before Atlas rises hit.
I would assume the same is happening this time too. We might get a proper screenshot of new ship and suit, followed eventually by a trailer on launch day.
@DarkbyDesign below, you know what maybe you’re right, element six could be this weekend and be a screenshot