Civilization VI's New Frontier Pass is expanding next month with the planned Ethiopia Pack. It'll be available as part of the season pass or you can purchase it individually (for around £4) and it's going to bring a number of interesting additions to the game.
Of course, the main draw is the addition of a new playable civ, which will be a faith-focused Ethiopia, with more details set to be revealed on that front in due course. In the meantime, however, we'll have to make do with knowing more about a few other interesting features joining the game.
One new feature is the diplomatic quarter, which will bring new bonuses to diplomatically-minded players - apparently it's "so powerful" that you can only have one of these districts per civ.
However, the most interesting addition (as far as I'm concerned, at least) is the new secret societies. You'll need the Gathering Storm expansion to access this content, but if you've got that during the course of a game you'll be able to join one (and only one) secret society, and each has its own benefits, in particular via new governors with four unique upgrades that operate in the background (and thus can't be assigned to specific cities).
The Owls of Minerva have an espionage focus, with gold-related bonuses. The Hermetic Order values science and innovation above all else, and they can see a new map resource exclusive to them: ley lines. Voidsingers, meanwhile, seems to be based on Lovecraftian lore and have a unique 'Cultists' unit that can be purchased with faith. Finally, there's the Sanguine Pack, which are basically vampires and could well be useful in the hands of an aggressive player (they also get cool-looking castles that you can teleport between in the late game).
Season Pass owners will also get new personas for Teddy Roosevelt (this version has an exclusive new 'Rough Rider' unit) and Catherine de Medici (who covets luxury items and can initiate a new 'Court Festival Project').
Expect to see more of the new civ, Ethiopia, in an upcoming dev diary.