Seperate maintenance windows for NA/EU would be great.
Maintenance starts at 3am US time, which is between 7-9am in EU, then when you have 18 hours of maintenance it wipes out any chance of EU being able to do anything.
If maintenance was started at 3am CET there would still be chance for EU players to do something based on an 18 hour maintenance window, rather than getting totally rolled over on, then this also means that other regions don’t get the same problems being experienced as the hotfixes etc have already been developed and tested.
Maybe this is the very reason that Blizzard have operated separate maintenance windows for each regions since the release of World of Warcraft.
And if you want to do release at the same time then fine, just put the patch out with that content in prior and set the unlock time for the future, that way all regions are on the same time frame, however until NA/EU/RU/JP get the content at the same time as KR (which won’t happen) does anyone really care about unified release times for content? It’s not like world firsts are even a thing.