Barbie's popularity is waning even if her price is increasing. If I were to think of a gimmick to promote Barbie, I would kill her first. Superman, the Lion from Narnia and Jean Grey all did it. I guess that is why Barbie is entering the superhero business, to die.
Imagine 5 years without Barbie. Trap her soul in the Cloud, no tangible toy, just some android game, like "Clash with the Clones" where she fights clone Barbie dolls who have taken over the world because they are more reasonably priced.
Barbie collectors will cherish all their dolls because they probably are going to be their last. The demand may build up. The dolls prices might increase in the secondary market knowing that there is no more supply. The amount people are willing to pay for a doll will increase.
And then she does a grand resurrection! Immaculate. Better than ever in all aspect--high fashion, better articulation, more durable with a god-like status.
OK, fine. Maybe it's no big deal if she remains dead.