User blog comment:ISharkyShark/Trading: Assumption of why it was added in 1.0.4/@comment-31479721-20170331171949/@comment-31479721-20170401201012

It all started with Update 1.4 for PC, the Pretty Scary Update. Since then, all PC updates have had themes, and I think since 0.12.1 or sometime similar all PE updates have been themed.