How would you feel about jobs getting new roles as an Expansion Feature?

FF11 spoiled me on DPS Dark Knight the whole dichotomy of spending health to do extra damage then draining it back again.

That got me thinking, what if instead of doing 1-2 new classes every expansion, what if one expansion each class got a new role they could switch to? They could easily reuse animations or simply change how some of the abilities work.

DPS Dark Knight

Healer Dancer

Tank Samurai

DPS Sage

etc

How would you guys feel about that possibility?