It's very accurate that Mirai defeated Ashley in 2014, but NOT accurate that Ashley was given Mirai's spot. As Skylark said, Mirai never had a spot. According to 2014 rules, the only person to directly earn a spot from Nationals was the champion (Gracie Gold). The other two spots were to be awarded from among the rest of the Top 5, based on the criteria list that was posted over the summer. The committee chose Ashley & Polina; they never said if their "order" was Ashley, Polina, Mirai or Polina, Ashley, Mirai. It is no more accurate to say that the committee went with Ashley instead of Mirai than it would be to say that the committee went with Polina instead of Mirai.
Perhaps Mirai's reactions (so excited & then tears) was partly due to the fact that neither she nor her team had paid close enough attention to the process & just figured that a 3rd at Nationals (with little else in the criteria to support it) would automatically be enough?