Hollywood has been plagued by unintentional leaks in recent years that reveal potential story details before the filmmakers intend for them to be known. These leaks don't come from insidious insiders or fans scoping out filming locations; instead, they come from toy companies that are simply showing off the tie-in products that they have for the upcoming films.
It looks like Rogue One: A Star Wars Story could be the next victim of details being inadvertently leaked by a toy manufacturer. In this case, the detail could be a major plot point as it reveals the possible involvement of a fan-favorite character that hasn't been seen since Return of the Jedi: Boba Fett.
At the Nuremberg Toy Fair this past weekend, the LEGO Group showed off some of its upcoming Star Wars product lines as part of a presentation for attendees. The slide mentioned all of the Star Wars product categories you would expect: The Force Awakens, Rebels, Classic Star Wars and Rogue One, along with what appears to be a "TV Series" category (which could be tied in to rumors of a new LEGO Star Wars series along the same lines as The Yoda Chronicles and Droid Tales.) The really interesting thing about this is that the Rogue One category features an image that bears an almost unmistakable resemblance to Slave I, Boba Fett's ship.
It's certainly within the realm of possibility that Fett could appear in Rogue One. The story takes place prior to the original trilogy, around the time that Fett would be making a name for himself as a bounty hunter, and it's already been rumored that bounty hunters would play a big part in the story. Other original trilogy characters such as Darth Vader and possibly even a young Han Solo are expected to appear as well, so it's not like Fett would be out of place. From a merchandising standpoint, having Fett (and Slave I) in the film would also give Disney/Lucasfilm an iconic ship for toys and other merchandise that stands out from the rest (similar to the updated Millennium Falcon and Poe Dameron's black X-Wing in The Force Awakens.)
If Fett (or at least Fett's ship) does appear in Rogue One, the question remains how big of a part he plays in the story. It's unlikely that it would be just a quick cameo, though it's possible; since he's an iconic character, if he shows up then he'll likely be one of the bigger threats to the heroes. Depending on how director Gareth Edwards ties the film in with the rest of the series, we might even see a nod to decades of fan speculation and have Boba Fett actually disintegrate someone (or possibly several someones).
There is also a Boba Fett anthology film rumored to be in development for a 2020 release, so it's possible that Fett will appear early to establish a new actor in the role and set up the events of that movie. Han Solo is rumored to appear in Rogue One prior to his solo anthology film, so why not Fett? With LEGO potentially letting the cat out of the bag, it's quite likely that we'll be hearing more about Boba Fett's possible inclusion in Rogue One sooner rather than later.
Rogue One: A Star Wars Story will be released on December 16th, 2016, followed by Star Wars: Episode VIII on December 15, 2017 andd the Han Solo Star Wars Anthology film on May 25th, 2018. Star Wars: Episode IX is expected to reach theaters in 2019, followed by a third Star Wars Anthology film in 2020.
Source: Making Star Wars