At last, you get some control.
In the original Destiny, your weapon and armor’s improvements and modifications were determined by a random number generator- however, it looks like Bungie is giving the player more control over the process in Destiny 2, with PCGamer reporting that the beta lets users and players modify the color and statistics of gear and armor to suit the user.
Of course, it seems that there will be limits to this, so that the balance and gear economy of the game is not thrown off. Essentially, it sounds like you will be using other weapons to boost your existing ones’ stats- so there will definitely be a cost.
It is also unclear if this will apply to Exotic gear, as well- it will probably not, given the general Rarity and utility of Exotic gear that Bungie probably wants to maintain. Destiny 2 is due out on PS4 and Xbox One in September, and then a month later on PC as well.