Since Blizzard is delaying Patch 3.3.5 one week after it launches in North America for Europe, Taiwan, and Korea, they are also delaying the Ruby Sanctum

The reason for the delay is to make sure the new Battle.net social function Real ID is working smoothly.

Blue Post: Due to the fact that we will be delaying the release of patch 3.3.5 in Europe, Korea and Taiwan in order to ensure the patch process in all regions is as smooth as possible, the Ruby Sanctum will not immediately be available on North American realms upon the release of the patch. Once patch 3.3.5 has been released in North America and we are confident about a time when we can open up Ruby Sanctum, we will provide an update here on the forums.