Yes, the terrain of the tactical map depends where on the world map the fight starts. If you’re ambushed in a forest, you’ll fight in a forest. If you’re out on grassy plains, it’s the opposite. The same goes for the lighting and weather. Fight at night, and it’ll be dark, fight under a cloud and it’ll be cloudy (or rainy).
Maybe there will even be tactical maps with structures, for example a bridge, houses or a castle (I remember seeing a cabin in the woods on an old screenshot). But that might be also a bit complex sometimes, because the hexagonal grid has no straight lines. Also if buildings are to high, like a wall for example, they’d block the players field of view. You can’t see what happening behind the wall, and there were already people complaining because the couldn’t see behind trees.
Edit: Last Saturday there was a new screenshot on twitter that shows some experimental clouds: https://twitter.com/OverhypeStudios