@flaki he's from Puerto Rico (a US territory) and sings almost exclusively in Spanish. He's also really popular, and a US citizen.
However, the fascists and slave catchers in control of the country don't consider him to be a citizen, and are very freaked out about it, and the singing in Spanish (oh gods, they are freaked out about the singing in Spanish.)
But the Superbowl organizers have been bringing in very popular musical acts to do the half time for years because more people will watch their favorite artists, even if bracketed by a boring american rules football game, than just the boring football game.