I’ve been thinking about this playing through the game, and I’m going to put a [SPOILER WARNING] right there so anyone reading this knows and is warned. If you choose to read beyond this point, I’m not responsible for the spoilery stuff you found.
So there are a number of reasons going through this that I think Mass Effect Andromeda can’t be a simple standalone game and will at the very least require a sequel. Perhaps not another trilogy, but at least a sequel.
First, I haven’t read the book yet but if you finished the Ryder Family Secret quest you know that Jien Garson’s death wasn’t because of the Scourge. She was murdered in cold blood, because she suspected someone called “the benefactor” ... a person with a lot of money and resources to make things happen. Jien Garson was just the spokesperson. I don’t know about you guys, but that reeks a bit of TIM... don’t think that Cerberus will make a huge appearance, but if TIM was involved, I wouldn’t be surprised at all to see a Cerberus cameo. Of course, this bit can certainly be explained away in a shadowbroker type DLC, but what Bioware plans to do with this avenue is yet to be seen. If this is covered in the books, someone let me know.
Second, the Kett are not gone. At the end of the cinematic after the final fight, we see a Kett ship with what appears to be the Archon’s second in command angrily grimacing at Meridian where we just took down the Archon. Not to mention, in one of the side quests we know that Kett command doesn’t end with the Archon. He was just the current influential figure in Heleus. There is a whole bunch of them like Archon out there who may very well take Archon’s death as a declaration of war.
Third, relations with the Angara are just getting started. Again, this is something else they can cover in a DLC but the relationship is still on unstead ground and we’re still only building the foundation of a relationship. And not to mention a great deal of Angara still don’t trust us or like us.
Fourth, and this is the biggest one, the Jaardan. We have been told there is a possibility they will return to finish what they started. And in a conversation with PeeBee after her loyalty mission she equates them with “the closest thing to gods we’ve ever touched.” But she goes on to say that the Jaardan were attacked and driven off. Which is clarified in one of the later story missions of the game. “The gods have an enemy, and it will also be unlike anything we’ve seen.” Which could very well mean there are even bigger enemies than the Kett to come. Why do I say bigger enemies than the Kett? Because in one of the final missions, the Kett get their asses handed to them by friendly Jaardan tech. There is no way the Kett could give the Jaardan enough of a fight to make them retreat into whatever netherworld they came from.
With all this in mind... there is a LOT of ground to cover that I really don’t think mere DLCs can do justice.