Canadians are normally admitted to the US through their own scheme outside of VWP, and thus the HR 158 restrictions shouldn't apply to a Canadian-Iranian.

The more and more I think about this, the more and more I wonder if the real intent of this bill's sponsors has nothing to do with post-Paris/San Bernardino security fears (though that certainly helped it sail through Congress) and the bill was actually a deliberate effort to either sabotage the JCPOA or to slow down the entry of European firms into the Iranian market, with the affected Syrian and Iraqi dual-nationals being collateral damage. I try not to buy into conspiracy theories, but I simply can't think of any legitimate security interest in going after folks like Rana Rahimpour. Given recent events in the region, I wouldn't be shocked if one found the fingerprints of KSA lobbyists somewhere on this bill...