In a recent faction change, it was found that all progress toward the weapons of conquest disappears. However, the character remains at 2200/2200 cap. And given that it will be what, 600 points a week these days (insane), You are now looking at 4 weeks before you can complete this quest.
Blizzard, this is an absolutely insane game design choice. You need to remedy this because you are crippling people who had no idea that a faction change ruins pvp quest progression when it is already shown in your total conquest earned that you have indeed completed 2200/2500.
You need to change this.