As mentioned, the order of the random articles should be stable... Assuming
that there are no changes on the wiki affecting that. Article creations,
deletions, etc. means that the articles on your list could disappear, and
reappear somewhere else, as well as new ones appearing between them. As an
extreme example, if you renamed each page to the title of the other, you
would get a list of the same articles in the opposite order.
Best regards