The title implies that the plot and action will be following Boba Fett, and that’s really where the issue lies. If the title were just a little less specific then it might bother people less. ‘The Clone Wars’ or ‘Star Wars: Rebels’ for example give the showrunners freedom to expand the scope beyond a single character.
But basically it seems we’re watching a timeline unfold, that’s linked to Boba but not exclusive to him.