From a predictive sense. I'm not sure if FFG would want to release APP news before HotE is released.
Pro: If they announce an app, it will probably build a lot of excitement throughout the gaming world. More excitement = more sales of all IA products.
Con: Releasing news of an app-driven campaign before/during the release of a non-app driven campaign might have people lose some interest in HotE.
Maybe they'll just tease us with some app news without a full announcement? Not sure how that would work or if it's really FFG's style.