That's a heritable trait, not selection pressure. Remember, we're talking about an infinite population size here, but if the pop. size was capped then the mechanism that decided who got to replicate and who didn't would be the selection pressure.
Can you ELI5 why you think the varying replication rate is, by itself, a selection pressure? Because your point's obviously going over my head, and your last comment did nothing to communicate it more clearly.
> At most, all you can say is that if you select a universe at random, it's likely to be a high-black-hole universe.
Yeah, that's sufficient when it's caused by their heritable properties. The proportion of high-black-hole to low-black-hole universes will approach 1:0.
Extinction is not part of the definition of selection pressure. Even in biology we still call it selection when a species merely gets pushed to the margins of an environment instead of driven extinct, or when a trait merely becomes uncommon instead of disappearing.
The low-black-hole universes aren't going to stop "procreating" because high-black-hole universes exist. At most, all you can say is that if you select a universe at random, it's likely to be a high-black-hole universe.
And I think you can use that fact to argue the theory's wrong: because surely our own universe is an LBH universe? A trillion is rookie numbers. There must be universes that produce vastly more black holes than ours, so the chances of us ending up in such an LBH universe at random are vanishingly small.
> And universes aren’t constrained by a shared environment with limited resources – newborn universes aren’t all competing in a valley with a limited amount of grass.
Yeah, that's what I'm trying to say. Without competition, it's not evolution.