This is such a fascinating idea. One can imagine universes in which the physical constants are unfit for black hole production, universes (like ours) fit to produce multiple black holes, and most interestingly, universes which instantly collapse into a giant black hole and "reproduce" only once and give birth to another universe that does the exist same thing, ad infinitum.
BTW, Martin, do you know if there are any theories (or even vague notions) as to what constants might govern the whole of the multiverse (to use a term you hate)? Obviously all of our physical constants would be arbitrary to it, and it seems that conservation of energy is also right out the window. I would imagine that every individual universe would be bound by some sort of conservation law, and that Newton's 2nd law would apply to them as well, but what about at the multiverse level?
Kind of puzzling to imagine that, at the grandest scale, there may be no real order.