Moreover, it involves regicide at the end: indeed, given the controversial political theme of the opera, it was subject to censorship.
As such, the composer was obliged to change the setting from royal Sweden to colonial America. The king got converted into Richard Warwick, the colonial governor of Boston ("Riccardo").
In more recent productions, however, the setting has been moved back to the Swedish royal court ("Gustavus"). I wouldn't imagine this version ever being performed in the country, but perhaps the one set in colonial America?
Or is the opera banned altogether in Sweden? I was told, on the Franco-Iberian board, that Verdi's DON CARLO(S) is indeed performed in Spain, insofar as it hasn't been banned -- notwithstanding the factual errors and historical inaccuracies.