Announced back in 2019 during Microsoft's E3 press conference, LEGO Star Wars: The Skywalker Saga will consist of every mainline Star Wars saga entry. That's everything numbered episode from Episode I: The Phantom Menace to Episode IX: The Rise of Skywalker. However, the cat's out of the bag; the game will also feature content based on The Mandalorian.
This leads us to believe that LEGO Star Wars: The Skywalker Saga will also feature content based on other spinoffs, television series, and anthology movies — such as Star Wars: The Clone Wars, Star Wars Rebels, Rogue One: A Star Wars Story, and Solo: A Star Wars Story. However, that's just speculation and certainly not officially confirmed so don't get your hopes up.
Content based on The Mandalorian, however, has been officially confirmed. The live-action Disney+ series debuted back in November and is quite popular, to say the least. It's not a mainline entry in the saga but rather simply takes place within the same fictional universe as the movies — just like the aforementioned spinoffs.
Earlier this month, LEGO unveiled a real set based on The Mandalorian. It's the titular character's ship: The Razor Crest. Those that weren't too busy fawning over the cute, little Baby Yoda microfigure noticed that the back of the set's box said that included within is a code to unlock the ship in the LEGO Star Wars: The Skywalker Saga game — as you can see below (via LEGO).

The galaxy is yours with LEGO® Star Wars™: The Skywalker Saga! Play through all nine saga films in a brand-new video game unlike any other. Fly across space to the saga's most memorable planets, in any order, at any time. A galaxy far, far away has never been more fun!
LEGO Star Wars: The Skywalker Saga is set to release for the PlayStation 4, Xbox One, Nintendo Switch, and PC in 2020.
