I opened the chest, it gave me 200 diamonds. Scouting costs and fighting already scouted provinces did not change. I forgot to check tournament fights, but probably those did not change either.
As Ashrem mentioned the chest has no impact on scouting, ideally it should be positioned immediately before the tech over the line. The chest is completely separate to the tech. The devs were having large problems with balancing aspects of the game because of a large variation in map expansions that players where earning each chapter. The chests were a way to ensure a minimum amount of provinces and therefore expansions were unlocked. While some level of restriction on the upper limit was done it has largely been ineffective.
The scouting tech will make a difference to your scout times, cost and difficulty of world map provinces. However it will not effect tournaments or the provinces already scouted, only those done
after the tech. The moment you click scout the difficulty and cost are fixed and don't change (not counting you getting bigger squads). Have a look at the scout time and cost of a province before unlocking the tech and again after it, you will see the difference.