Likewise, as development began on the evolution of our Factions mode from The Last of Us: Part I, the vision of the team grew beyond an additional mode that could be included with our enormous single player campaign.
The Last of Us’s original Factions multiplayer was a part of the craze of every single player game needing to have a multiplayer mode for a limited time, and while that often went poorly for many games where it seemed tacked-on, Factions actually developed quite a fanbase, and is thought of fondly by most players to this day.
It seems that Naughty Dog wants to build on that, and I would not be surprised to see a much larger investment in Factions this time around, especially judging by that statement they released almost a year ago.
I could foresee them doing the original Factions model with its different modes, but also something like a smaller scale battle royale concept, where players stalk each other on a map in the vein of PUBG style gameplay, perhaps.
In short, despite the silence, I would imagine that Naughty Dog is very much working on Factions as its next project