I’m in Australia and have had access to the game since I got up about 12 hours or so ago. I searched the store for Assasins’s Creed and it showed up in the search results. Clicked on it and it downloaded (I have the Odyssey season pass).
It then took ages to download-About 22GB of essential files, after which the game will play but without the extras. 65GB in total. I have no idea whether I got the day one patch-there was no separate download for it and it hasn’t auto updated.