Last year for the Taurus wagon was 04. AFAIK there are no plans to make a wagon version of the latest platform. Seems everyone these days wants a top heavy, ill handling, rotten gas mileage SUV or crossover instead of an, IMO, much more useful wagon body style.
The Taurus X is not a Taurus at all. Its the Freestyle rebadged. It also much smaller (though it rides higher) than the Taurus Wagon.