By truly random you mean uniformly distributed (distributions other than uniform are just as random as the uniform distribution). Does it say somewhere in the description that the wild magic options are uniform? There's no reason that one wouldn't be more probable than the others. Even if they are uniformly distributed, you still expect some player's sample distributions to look like they were drawn from a non-uniform population, since there are many players playing. That's how randomness (whether uniform or otherwise) works.
