I feel like no one is going to play a light soldier, or even soldier at all ... Just a thought though, probably have plenty of soldiers of all body types
My main will be a light soldier, can't over look how important they are to objectives as well as how useful their abilities are for various roles. Certainly they aren't in the same distinct classifications as Medics (obvious need), Engineers (obvious toys), or Op (obviously not obvious), but they have enough stuff to make them a great class.
EDIT: And the most underrated class (sub class since classes can fill multiple roles based on specs) will be the non-healing focused Medic. They have a collection of tools that could make them great at things other than healing/ressing, but people are going to expect every medic to be a "medic" in the strictest sense of the word.