I don't think these are DLCs, expansions, a patch, or something to do with the launcher. This is new, whatever it is. It's possible that these are more powerful modding tools that they are finally permitting modders to use.
Please stop giving me Hopes!! There is nothing that would make me more happier than that, and if that's true then I'm gonna preorder Civ7 when it's available just to support Firaxis. Otherwise I'll be waiting till the 1st or 2nd big Expansion DLC.
But honestly, I doubt that's the case. I think it has to do with last Year's 30th Civ Anniversary Announcement of new things that would have been released throughout some Months, especially since they just postponed that for a Year now that we got the Civ Merch 2 weeks ago.
My guess is that it's a Spinoff Game that contains stuff from all Civ Games, which got postponed either bc of Midnight Suns or bc it wasn't ready back then.
I would be happy with anything at this Point, a Game Update/Bugfix Patch, a Lua API, more modding possibilities, a tool to create database Effects/Requirements..etc. Though a DLL would be the best thing that could happen to Civ6 IMO, better than any Update/New Content.
EDIT: So this has to do exclusively with Civ VI right?