8.0 speculation

[Turnintino]

And a message, coming from an Ancient, for the WoL, who clearly knows who the WoL are, what kind of people they are, and all about their goals and fate (the word is used) and asking us to continue our journey and "Unite the stars into one".

First of all, I think you should add spoiler tags to your post, since 7.5 is still very fresh.

But as for the scene in question...

I personally interpreted this as the WoL recalling Azem's memory of their commencement to the Convocation. If I'm correct, the key likely precedes them; an earlier invention given to any who hold the seat in question, apparently to ease their travels.