Yes, that's exactly the only thing to say in this case.
-there are 2 data-centers: japanese, and american. Europeans connect to the US datacenter, so if they set that maintance in a good hour for americans, all europe get screwed. Just like they did in FFXI, where every maintance was in my primetime, 9:00pm to 12:00 am
-also, not everyone connect to a datacenter near him, americans can connect to japanese datacenter and vice-versa, and so all the rest of the world
-aside the urgent hotfixes, like the security breach in the market ward or others urgent issues, maintances are usually 1-2 per week, they are not nearly as frequent as people try to make. "Nearly all nights downtimes"...yeah...
So let's say, they shift maintance time in a good hour for japaneses? US get Screwed.
They shift time in a good hour for US? Europe get screwed.
They shift time in a good hour for Europe? Japanese get screwed.
The world is round: there's no way to fix that, so i suppose every hour you choose will always end hitting someone. How people think it's possible to fix it, it's in the realm of sci-fiction.