Are the start times being staggered by world, or are the start times on each individual world staggered by battleground?
If it's the former, the scheduling issues aren't a huge problem, if it's the latter than it's a big problem unless the start times are pre-announced.
If you're going to stagger start times in an unpredictable manner, why not move GBG start to the evening when schedules are at least somewhat more flexible for most people?