Just to clarify, for anyone who was interested and hasn't read the accounts elsewhere. There are 8 voting regions in the US Masters for this. In order to change systems 7 out of the 8 had to vote to switch. Kings of War was a clear strong option for the change, but instead of splintering any possible opposition the initial vote was just "Kings of War" or "Any other system". Honestly nobody really considered AoS as it is not a viable option. But 9th age, sticking with 8th, coming up with a US Masters comp/8.5 were all options.
A great deal of time was given for regional reps to go back and discuss it with the TOs and local players and figure out what each region wanted. When they came back there were 7 regions that voted for Kings of War, and one region that was internally 50/50 split between KoW and something else, and so they choose to vote against, but it was a "soft" vote against.