Lyrics Censored: "I'll rip [Mystikal's] voice box out and scream in his ear."
The mixtape was released on Interscope, a Universal company. At the time, Mystikal was on Jive, a Sony company. So because there's no label conflict, it has to be because Sway and Tech really liked Mystikal. Eminem sarcastically disses plenty of other people on the track.