It's a bit odd that there is only one new faction- will there be a new third axis faction?
There is no official confirmation. However, game files that previously hinted at British faction also hinted at new commanders for OKW. So a likely scenario is that Brits come out with 6 commanders as USF did, then OKW gets another 3-6 commanders. Not a new faction, but very likely several new units/abilities.
My
personal theory is that if the Brits are themed around late-war Italian campaign, the new OKW commanders could be themed around this too, providing Italian auxiliaries to the core German army.