So the same japanese dude that leaked the how content did more digging, xur is set up my pre built templates (these can always be modified) however in all the templates built up to september that he found, gjallarhorn is not even on there once. Believe what you want, here is the proof, he also posted a picture of qhat xur was selling last week which was 100 percent on point. http://www.reddit.com/r/DestinyTheGame/comments/2wi7fq/misc_about_xur_sale_list_iron_banner_sale_list/