It’s an analogy, the specific case doesn’t matter. It demonstrates that infinite does not mean literally everything, it’s possible for some item to be missing from any particular infinite set. In a box of infinite apples you won’t have an orange; in a box of infinite fruit you won’t have a chicken; in an infinite multiverse you by definition won’t have a universe which isn’t part of that multiverse.
Where I am you can buy part-baked bread and “well fired” rolls.