There is no official continuation. BP is as close to be FS3 as every other post-capella mod, all continuations are independent timelines and equal in this regard. Community consensus is: There is no such a thing as Fanmade FS3.
Between the Ashes is set between FS1 and FS2 and tells no story about continuation of FS2 events. Derelict is more like a expansion pack for FS2 rather then huge story on it's own.
Feel free to think about possible ideas for FS3. We're brainstorming stuff like that from many years, but no mod will ever be accepted as "the best, community-approved continuation".