I suspect that this is a requirement for Apple to not favor its own products. Any ordering other than random would implicitly have Apple at the top of the list

I suspect that this is a requirement for Apple to not favor its own products. Any ordering other than random would implicitly have Apple at the top of the list and then you've got lawyers and regulators asking questions again. Having it be random avoids that and Apple can clearly point to the "the order is random, we cannot favor or disfavor ourselves or anyone unfairly."