I am disappointed that the chapter was rushed but the people in Jump probably made Kubo rush it. Anyway, after reading, the big announcement might be a new sequel or most likely the continuation of the anime. The black goo must be Yhwach or Ichigo.
But there are still A LOT of plot holes and questions. I don't think all of those things will be covered in the final chapter. Nevertheless, I will still read it as I have been following this manga for years even though I am not expecting a good ending.
For me, this chapter was a 3/5.