Here's yet another reason not to include in any contract you draft a clause -- whether relating to arbitration or anything else -- that says "X, but X may not be valid in California."
At least if you personally would like X to be the case, just say X. Whether X is enforceable or not, leave that a question for another day (and another forum). Because otherwise, by saying the rule is X but maybe non-X, you definitely won't get X.
So just say X.
