With Bungie you never know if it's actually a key to a Easter egg.
The Stranger hands it to you. This could be Bungie's way of saying this is important for other things.
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I dismantled all mine a long time ago. I had three characters, then deleted one and started over, then did that again. I've had a total of five fully levelled characters. I never finished the last story on my newest Warlock until two weeks ago; got to level 20 beforehand. When I got the Strangers Rifle this time, I locked it. I ran around with it for a day and had a lot of fun with it. Since it is a low level gun, it still sucks though.