The Mandalorian season 3 won't be the same as Book of Boba Fett. Lucasfilm surprisingly confirmed that the classic Star Wars bounty hunter is indeed spearheading his own spin-off with Fennec Shand. But due to the lack of additional information about it, there were some confusion regarding it.
Years of speculations about Boba Fett's final fate after falling into the Sarlacc pit in Return of the Jedi were finally laid to rest at the start of The Mandalorian season 2. He was revealed to be living quietly on Tatooine, although it's unclear how he survived. He returned in a later episode titled "The Tragedy" where he tracked down Din Djarin and Baby Yoda on Tython to reclaim his armor that Mando had received from Mos Pelgo's Marshal, Cobb Vanth. From there, Boba and Fennec helped in rescuing Grogu from Moff Gideon, and with that over, went back to Tatooine and reclaimed Jabba the Hutt's former palace from Bib Fortuna in setup for Book of Boba Fett.
Other than starring Boba Fett and Fennec, not much is known about the Book of Boba Fett, but it's been confirmed to arrive in December 2021. This was exciting until the realization that The Mandalorian season 3 is also set to debut around the same time. Given this, speculation began to swirl that the deemed spin-off was actually the next chapter of the live-action Star Wars series, but according to Lucasfilm artist Paul Bateman this doesn't seem to be the case as the projects have different production schedules.
As Bateman mentioned, he doesn't represent Lucasfilm, so whatever he said here shouldn't be taken as official news. Since the episodes of The Mandalorian have been titled "chapters," it's possible that after Din Djarin's time as the titular character, Boba Fett is next in line. In that case, the show would become more like an anthology than the serial it has been thus far. That being said, if The Mandalorian and Book of Boba Fett indeed have different production schedules, perhaps with different people involved, it makes sense that they'd be entirely separate series. It's worth noting that at this point, it's unknown what exactly Book of Boba Fett will be. It could even be an original movie for Disney+ which would release around the same time as The Mandalorian season 3 as an accompanying content.
Whatever the case may be, there's still a lot of things to be excited about Book of Boba Fett; the project gives Lucasfilm the opportunity to properly flesh out the fan-favorite character best known for his armor and the hilarious way he fell into the Sarlacc pit. It can tackle how he survived the events of Return of the Jedi and what he's been doing since then. The same could be said with The Mandalorian season 3 given the events of its most recent finale. While Mando and Baby Yoda are now separated, chances are that they'll eventually find their way back into each other.
Source: Paul Bateman