Oceania Twisted Treeline

Why is Twisted Treeline not permanently out on the Oceanic Severs? I know that there is a scheduled rotation on the days it is available, but I recall when the Oceanic servers were released, they said that they were working on having The Twisted Treeline working, however, it has been almost 2 years now. Not only would I enjoy the Twisted Treeline for normal games, but for ranked team games, as 3v3 ranked team games with my friends where incredibly fun and different compared to the summoners rift. If we could please have some feedback to when this is being released, that would be great. Thank you.