I think the old balloon analogy of the universe can be applied to black holes. If one makes a pucker in the surface of a balloon and gives it a twist trapping some air inside, that would be similar to the formation of a black hole. We observers on the (spacetime) surface of the balloon see only the highly distorted (curved spacetime) rubber skin left behind but we don't see where the missing part of our (spacetime) rubber skin has gone. It has gone into the black hole which is a mini-balloon universe of its own.
Black hole formation converts normal, weakly curved spactime into highly curved spacetime thereby stretchingthe space that remains on our side of the Schwartzschild radius and this could contribute to the appearance of expanding space.