As the title says... it’s a blue Maybe something that can be later upgraded to a purple then a gold? Thoughts?
Personally, I believe Bungie just added a blue Bow and Machine Gun so that free/DLC-less players can enjoy these weapon types earlier in the game. There's only been Legendary and Exotic How's and Machine Guns before, and quite a few of them are currently unavailable.
All blues are available from collections though...?