For comparison as Gumbuya World have the same coaster.
Groundworks began July/August, foundations began in September, with track install soon after and was completed late October/early November. Testing began late November and it opened late December.
So far the timeline for Wizard of Oz has been; Arkham Asylum was removed in June 2022, Wizard of Oz was announced in July, site works began October, track arrived April 2023 and foundations/footings began construction Novemebr 2023. And the land won't be opening until late 2024. I understand there is a lot for to be constructed other than the coasters for this land, but so far construction has been very slow.
If it opens in December 2024, we are looking at a 2.5 year project timeline from AA's removal to it opening.