In Row 59 of the feedback spreadsheet in Kickstarter Update 61, Owlcat states the following:
Nearly all the companions are ready and we can’t change them. But there are two unrevealed companions. One of them will have focus on Strength and Dexterity, the other - on Intelligence.
The intelligence based companion is likely a full caster of some sort, but I suppose could be a Sword Saint or alchemist. I’d bet on an Arcanist because it is a new class, and because Owlcat has already built an alchemist and a magus in KM.
What are people’s thoughts about the strength and dexterity character?
A composite bow user seems unlikely because of Lann and Arushalae. For the same reason, a switch hitting ranger seems redundant. Strength and Dexterity would suit a Fury’s Fall, trip Druid, but we already have so many divine spell casters. Maybe an AOO Polearm user who uses combat reflexes and has armor training? Or perhaps a TWF build—but that would be extremely MAD and suboptimal compared to a slayer/ranger build.