The patch is slated for 22nd in Japan, so I would assume that it is the usual time in all regions, i.e. 9 or 10 pm on the 21st UK time.
As for the hubs I am looking forward to them, I also assume there are actual quests here, I can't imagine SE would implement them without after the number of features they have postponed when there wasn't anything for them to do. The only slight disappointment I have is the buildings are the same in each pair, I wouldn't have thought it would have been too difficult to have different ones.