FIM is dependent to national / local clubs to organize the World Cup events. And as long as there are no clubs, who have the appropriate site and the necessary assistants, there will be no trials with long hill climbs, muddy banks and river crossings.
So I'm afraid that if you want a world cup that suits your needs, you'll have to organize it yourself.
Don't get me wrong, I'm all in favour of more variation in the events, and sometimes get bored with all that rear wheel hopping too, but I'm also glad we still have world cups, it's not that evident in these times.