More details will be revealed next week.
Star Wars Battlefront II is keeping up with the latest films in the franchise, and this allows players to enjoy new content from the films in the game. When Rogue One was released for example, the game received some new content in the form of some new maps based on planets shown in the film, new heroes from the film and more. Now, with the upcoming film Solo: A Star Wars Story on the way, the game will be receiving new content based on the film.
As for details about the date or about the content itself, not much has been revealed except that more details will follow next week. At this point, we can reasonably expect the new content to include some new maps and skins at the very least. There is a possibility that some new heroes may be introduced as well.
We’ll just have to wait until next week to find out more.