Feels more like a cancellation than a completion. That doesn't seem like it was supposed to be the end.
On the other hand, it's actually a decently good stopping point. Not the best (a bunch of plot points are still in flight), but it works—in a series built around turmoil, it stops at a point of emotional repose. And some much-needed catharsis is really there in the last few chapters, whether or not it was supposed to be a wrap-up for the whole series (and there's no concluding note as such, except on the small-time level as one would expect for the end of a story arc).
Now—it seems pretty clear to me that a bunch of unresolved stuff was probably supposed to go wrong in the plot after this, but stopping without that happening isn't so bad.