I believe that that theory is about un-padded numbers. It doesn't apply to fixed-length numbers generated in the full range. Because 010 would have a leading 0

I believe that that theory is about un-padded numbers. It doesn't apply to fixed-length numbers generated in the full range. Because 010 would have a leading 0 rather than a leading 1. Since the first byte of a UUID is random and can be any of the allowed values it has no bias in the first digit.