Not necessarily: consider a string of '0's and '1's' both infinite and random.
011101010101000....
No matter how long you look, you'll never find a '2'. Same with the multiverse, not all things need to exist.
I was about to make a comment about, how a double pendelum can swing in an infinite amount of unpredictable ways, none of which will suddenly turn it into a car. But I like your analogy so much better.
And even an infinite number doesn't mean all. There are infinite numbers between 0 and 1, none of them is 2. So the multiverse wouldn't have to include one that contradicts its rules.
infinite universes all with the same physical laws, but every unique possibility
What makes different possibilities exist if the laws are the same? Is there a random function somewhere in the laws of physics?
You can combine the same atoms into different larger elements. It's like that. The same physical laws, but the combinations are infinite (or at least uncountable).
The other concept is that the laws are different, but not true infinite combinations within reach.
Or both.
The question is if the laws of physics are deterministic or not. If the rules are the same, then the result would be the same and all the universes in that case would be identifical.
The multi universe theory assumes randomness, undeterministic physics or that every universe has different initial properties.
Maybe in the sense that the people there haven't thought of the theory itself. But one universe can't affect if a multiverse exists or not, one universe would just be part of a whole
I'm assuming the one where you believe that every conceivable series of events happen.
That or it's the fictional multiverse where every permutation of the set of every fact being true exists.
Going on the rule that the multiverse theory is accurate... Then I do believe that makes the end statement impossible.
The multiverse isn't dependent on any single universe. So if multiverse is true, and a universe exists, it wouldn't be possible for the multiverse to not exist as that would be a logic paradox.
Of course, it's from a matter of perspective. Those in that universe might not be aware of capable of recognizing or conceiving the multiverse. But that wouldn't alter it's existence. Kind of like a one way mirror.