Back when Star Wars: The Last Jedi got pushed out of its original May release date, Disney filled that spot with Pirates of the Caribbean: Dead Men Tell No Tales.
The live-action Lion King movie currently has a release date that had previously been given to Indiana Jones 5.
When the same thing recently happened to Star Wars: Episode IX, the spot was taken by the live-action remake of Aladdin.
It’s absolutely true that Avengers: Infinity War received its release date first, several months ahead of the official announcement of Solo: A Star Wars Story, but it’s not like Disney hasn’t needed to shuffle around release dates before.