The Mystery of Tetris in Ericsson's A1018s firmware

Ericsson phones in the first couple of years of the 2000's often included Tetris. Why did Ericsson then slip Tetris into an older model phone from 1998 and limit the firmware only to Eastern Europe? Exploring the Ericsson A1018s, building a service cable and flashing the firmware into an A1018s. Music: DJ TR!P Song: Janus Cycle (Control)