They are complaining because a spaceship named Slave-1 (which is extremely famous and important as we all know) has been renamed for a LEGO kit as "Boba Fett spaceship".
Which is obviously SJW censorship and not simply a maerketing play because the name Boba Fett is more famous than "random ship-number".
I remember being a kid when the prequel movies came out and doing a double-take when I heard the Slave 1 ship toy being advertised. I didn't get the best education growing up, but I remember it felt off to hear the term used outside the context of US slavery.