I've had a few drinks so this might not be as coherent as I would like it to be, here it goes anyway... What you have suggested is a paradox so it would not happen. An infinite number of events would occur to stop this scenario from occurring. The only way this ever could happen is if the universe we inhabit had never existed at all and as this universe does definitely exist, to the best of scientific knowledge, we know this to be true... It's like saying that In an alternate universe the universe never existed?. There could not be an alternate version of that 'universe' because it never existed to begin with. Matter and antimatter are not equal in our universe. Sure there will be universes where antimatter is dominant over matter but never to the extent that matter is absent. There can be no antimatter without matter and vice versa. Anyone else want to take a shot at this?.

Wow.... 😜