It's very unlikely. Chris doesn't want such a full simulation, as it is prone to balance issues and virtually any game that has such things heavily cheats to stop one side from just taking over super fast. For instance Mount and Blade and Total War do this, so the player doesn't get railroaded by some massive empire before they were ready.

Also, they're building a world full of interesting places, character, and factions, they don't want a player to miss out just because some random warlord on the other side of the map decided he wanted new land.

A full war simulation is not something that Kenshi is supposed to be, nor something the devs want out of it, it's an RPG game first and foremost. Chris has said he does want faction interactions to be a little more dynamic though, so I expect we'll see some form of interactions between them, but nothing as extreme as actual conquest or anything that would have major effect on the world.