We know that Bungie is in a agreement with Activision for a number of years but so far we have not been told which, or how many games they are going to make with the publisher. Documents from a recent lawsuit might have shed some light on that, especially with regards to Destiny.
In the lawsuit’s documents it was mentioned that the developers is to make multiple episodes of the game which will span across a number of years. Here’s an excerpt:
In 2010, Bungie entered into a ten-year development and marketing agreement with publisher Activision Publishing, Inc. to fund development of Bungie’s new first-person shooter video game that later became Destiny. The agreement anticipated the issuance of multiple episode of the game over a period of ten years. The first game was scheduled for release in September 2013.
Alongside that, another piece of document was shared that revealed five codenamed projects that have to be completed by Bungie by 2020. As you can see in the image below, it lists four releases for something called “Project Tiger.”
The first of these was originally scheduled for September 2013 (and we know that Destiny was delayed a lot), and the second one was originally scheduled for release in September this year. We are assuming that these are the original release schedules that got changed with time, and the first four projects are possibly referring to Destiny and its expansions.
There also is a four Bungie game which they have codenamed “Comet 4,” this one is scheduled to come out in September 2020 leading to the end of their agreement.
So if they are considering The Taken King as the full retail release, it means we are looking at two more of the same scale in the future.