The question I've been wanting to ask about Black Holes is not whether they'll be in the game.. it's whether they will be ... err... "game-ified"....
Let me explain - perhaps Black Holes thrust you into Witchspace where the Thargoids live. Perhaps they (Thargoids) pour out of black holes to invade our galaxy...
Perhaps you can use Black Holes to artificially increase your jump range by skimming/skipping along the event horizon (slingshot effect).....
If any of these make it into the game, then Black Holes will become more than just an interesting sight to see, take screenies, and then we move on.