While Bungie has never confirmed it we all know the last 3 DLCs or expansions or whar ever you want to call them are from cut content. And if the stories are true and Oryx was the final act they have run out of cut content. They may have bits and pieces here and there they can use to create special events or mini quests. I really doubt we will see anything worth while for some time.

Everyone said the same thing after Crotas end. Then they said the same for HoW. And now people are saying it again. Trust me, bungie and Activision have a cash cow, and they are not going to let it slip away. Destiny may not be what everyone was hoping but in terms of business, both companies have done very well to profit so greatly. And if there is one thing that we all know it is this; those with power and money, only want more power and more money. So no, destiny will not die until it's ten year plan is complete, whilst there is money to be made both companies will do what is needed to keep the money flowing.