Bungie defenders can't use the excuse that the schedule is too full anymore. We've had 2 empty weeks with nothing. These weeks are perfect to have IB as a filler. Bungie just can't take the easy win. They must have something personal against the event.
They're too busy trying to push their half-baked Heavy Metal mode and Call to Arms "events" to care about Iron Banner in any serious way. Just remember they pushed the original armor for our last Iron Banner into Eververse and gave us a recolor of an old set after saying they had something "new and badass" coming.
Iron Banner is only beaten by Gambit when it comes to neglected game modes.
Forever delayed in favor of Arms Week, Call to Arms, Guardian Games and Heavy Metal events that are more likely to generate revenue for Bungie.
Iron Banner doesn't really generate revenue for Bungie. it's basically a free handout of some of the best armor and (sometimes) good weaponry. As such, it has the lowest possible priority in the events calendar.
Don't hold your breath.