It was originally scheduled to open in Spring 2020, but it was delayed to October 1, 2021 as part of Walt Disney World's 50th anniversary celebration, since the opening was postponed indefinitely following the closure of the park, due to the COVID-19 pandemic.
However, on November 19, 2020, EPCOT has just announced that a new shows' massive barges will be permanently installed on the World Showcase Lagoon, offering an ambient feel during the day. 
This new show celebrates how Disney music (in multiple languages) inspires people around the world, featuring massive floating set pieces, custom-built LED panels, choreographed moving fountains, lights, pyrotechnics and lasers.
HarmonioUS is one of the largest nighttime spectaculars ever created for a Disney Park. The show is a beautifully crafted dreamscape of Disney music and images, reimagined by diverse cultural musicians and artists from around the world.
It is a transformative experience where we can discover how Disney music has the power to inspire and unite us all with the magic of possibility.