After listening to that planet destiny podcast with Luke Smith, I got the impression that they knew exactly what players were going to do with the three of coins that first week. He made it seem like not every rng exotic was available in the engrams that first week. Like players who spent all of their coins could only get certain weapons and armor. I really don't like to buy into elaborate behind the scenes theories, but that podcast sure made it seem like that first week wasn't totally a surprise to the devs.