As another data point, this happened to me last year. In the 2017 category change list, the Miami Beach EDITION was supposed to go from a Tier 3 to a Tier 4 property. In March, it did indeed change to a Tier 4. Then a month later it changed to a Tier 5, where it remains. I called MR and pitched a fit, and they allowed me to apply a Tier 4 award to the booking.