Despite being announced at the 2017 D23 Expo, Walt Disney World is now stalling (or possibly cancelling) plans to build a “broadway-style” theater in the Magic Kingdom.
It seems that the project is at least delayed, if not cancelled, due to some unforeseen circumstances. Despite blueprints and permits already being finalized and filed, the theater will likely not open in 2020 as originally announced.
It is very possible that the project is simply delayed. The current construction timeline would allow Disney to halt construction for 12-15 months, but still be able to open the venue by the 50th anniversary of Walt Disney World in October 2021.