For the first time since the Unova update, tiers are going to be updated. Usage based changes are made based on the usage gathered from February, found in this thread:   Notably, the way we're going to do usage based movements is different now. Usage will now be done in 3 month cycles, with normal usage movements (4.36% cutoff point) at the end of a cycle, combining the usage from the prior 3 months into 1 large aggregation of usage. Notably, the older months in the cycle, 1 & 2,