When anyone quotes their map by how many square kilometers it represents, that almost always indicates to me that realism is a priority before compact, flowing game design. So I'm gonna predict it'll be a lot like vanilla S.T.A.L.K.E.R. Dense adventure sites with lots of wilderness around them. Then they will back fill the void with things like random quests, caches, ALife (any word on that?) etc....
TBH, if it's a constricted, encounter-dense map design with a high interaction/sq. km ratio, it wouldn't really feel like S.T.A.L.K.E.R. to me. Despite all the dead space, that was part of what added to the game's desolate feeling.
I think the intent of the original S.T.A.L.K.E.R was that ALife was supposed to provide all the entertainment out in the wilderness between points of interest. The way it turned out, rather, was that ALife created pockets of hazards to ensnare the new player, and to be avoided by the veteran.
With any luck it's going to be a proper open world, but even just something like the OG map with direct physical connections between areas instead of loading screens would be nice.
Hopefully they're up with their streaming tech. I always thought, even back in the day, that S.T.A.L.K.E.R's zone transition screens were one of the awkwardest and most amateur-looking parts of the game.