As I understand it, Advanced & Masters will change every 2 years, but on the same year as FAI F3A: the one year is to make this adjustment in 2015 for the 2016-17 cycle.

Another way to look at it is that the proposed Advanced & Masters sequences are more difficult than the last cycle: they are only one year sequences, so if the increased difficulty needs to be reconsidered for the 2016-17 cycle, there is the opportunity to regroup on that point before a 2 year cycle goes into play.