I am fairly confident that we will get a new region in this generation. I don't think that it is referring to gen 7 because there wold be no point. Of course we would be getting a new region, as it is one of the main staples in the series. The way they specifically tell you abut this region, makes me think that we will be seeing it in gen 6.
For what the region will be based off of, I think that it will be either Belgium or Germany. This is because they are both towards the east of France and the train station in Couriway town, goes through a tunnel, that leads this way. I would hope that the new region would link with the regions that Kalos was at war with as well. In real life, France and Germany have been at war, and Belgium was where most of WW1 was fought, so these are definitely possibilities in my eyes.