I think henry will start recruiting his own army to hunt down the remaining bandits and cumens. There is concept art of cumens robbing supply wagons in force and men trying to stop them. Also there were concepts of massive open battles which never happened. it would be cool if we get a full battle on open ground with henry the commander where he can make tactical decisions that affect the outcome.

also all of the dlcs are content that happens before the end of the main questline ie the ride into the sunset so i think this one will be as well