We already knew that Obi-Wan stayed on Tatooine to keep an eye on Luke, so it's a given that most (if not all) of this will be set on Tatooine.
That said, yeah, I'm getting kinda tired of all desert, all the time. The Mandalorian had something of a space-western gunfighter vibe going on, so it kinda fit, but The Mandalorian did manage to visit a number of other planets. Boba Fett stuck around Tatooine because he somehow decided he wanted to run one of the towns. I think both of those series missed the opportunity to show us a larger, mostly-unexplored Star Wars universe. The Mandalorian tried, but got sucked back to Tatooine anyway. Now it's time for more stories set on a desert planet that honestly has no business being such a center of activity in an empire that spans countless planets in countless star systems. Yet here we are.