Although "Britannia" has never explicitly confirmed its positing of the young protagonist Cait (aka "The Chosen One") as the girl who would become the once-forgotten and later celebrated Queen Boudica — the real-life Iceni tribe leader who led the largest, bloodiest, and most nearly successful military revolt against the Romans in approximately 60 AD (via Britannica) — the timing certainly suggests that's the intent. While neither trailer necessarily confirms this development, we do hear the Druid Veran explain that "it's not what she's done, it's what she's going to do," in an eerie and enticing voice over, while Cait throws a dagger at Christian cross carved into a tree.
For Epix's part, the streaming service has confirmed that viewers will see "a radical transformation...(in) the Chosen One," as well as "a decision that will tie her to the future of her war-torn people and their ravaged land." With regard to the rest of the series' cacophony of competing forces and characters, Epix states that Season 3 will see Amena trapped "in a lethal ménage à trois" with her lover Aulus and his wife Hemple, while Cait's fumbling mentor and protector Divis "gets a new job which he despises," and the enigmatic Veran "goes to the underworld and sees the future."
For now, unless fans are also able to travel to the underworld, they'll have to wait until January 16 to see if hope will truly come in the form of "the daughter of a blind father," as the Druidic prophecy suggests. In the meantime, they can always throw on some Donovan, light some candles, and purchase a book about the historical clash of cultures from Amazon — you know, the folks who unceremoniously and, in retrospect, unwisely, passed on renewing the beloved series.
