False, the only way you earn an exotic is through accomplishing tasks that are out of the category of casual play, and working towards set goals, in the form of a bounty that has things to complete in order to earn it. But, to everyone who got Gjallarhorn on Week 2 from Xur, everyone who got a Gjallarhorn from some form of RNG, and everyone who got Gjallarhorn today, Congratulations. Enjoy it while you can, because, you know, it IS a Gjallarhorn no matter how it was received.