Just because there's no ticket types on JV routes does not mean that there's no campaign fares. On non-JV routes, booking codes for Light and Value can earn as Campaign. If I recall correctly it shows with a 0 inserted in the fare basis.

Also "Light" as nothing to do with Finnair ticket types on JV routes. It's a fare class of the JV. It just so happens to have the same name for the same reasons, bag allowance. With that said, I don't know how the Campaign criteria is coded in the fare basis for the transatlantic JV, nor the Japan one for that matter. And I would hardly be surprised if there was no ways whatsoever to see it before payment.

Admittedly, it does contradict the Finnair Plus published rules that tickets without types earn according solely to the booking code. But it would not be the first time that the fare basis leads to lower earnings than expected: it was already happening with AB-operated code-shares TOUR fares (when AB was still a thing). They really should stick to W code for transatlantic campaigns.