I think what he was getting at was Evo 1-6 was designed to be homologated to win the WRC as a Group A car, where for the Evo 7 Ralliart had moved onto WRcar specs which has little relevance to the road car and then wound up their WRC program.
Evo 7-10 has still been run with alot of factory support in the PWRC with lots of sucess so there still is alot of competition relevance in the later cars.
Sounds just like this, except you already knew what you were talking about, and I had to google it!!
In 2001, Mitsubishi was forced by the FIA to race in the WRC using WRC rules for building a car instead of the Group A class rules, and thus did not need to follow homologation rules. The Evolution VII was based on the larger Lancer Cedia platform and as a result gained more weight over the Evolution VI, but Mitsubishi made up for this with multiple important chassis tweaks. The biggest change was the addition of an active center differential and a more effective limited-slip differential, while a front helical limited-slip differential was added. Torque was increased again to 385 N·m (284 lb·ft) with engine tweaks that allowed greater airflow, and horsepower officially remained at 280 PS (206 kW; 276 hp).