Noticed it in late Nov when making the December calendar. Have the date history here: December 2021 TENTATIVE Calendar (Events: Trials, Rare Quests, Mirages Of Omega, Challenge Festival, Tower Of Magic, Tavern Of Legends, Atlantis Rises, Valhalla Forever, S4: Voyagers Of The Underwild, and Mythic Titan) - #13 by VeryQuietly
So there wasn’t an official announcement but seems to be consistent.