Never gonna happen. Grens can be reinforced on-the-fly from a HT behind a wall or a command bunker from behind the damn wall (Fix that relic).
Its cons which need a buff. They are useless late game in which they become a merely caping unit.
Sovits are the strongest faction at the moment for a number of reasons. Any buff to cons without some kind of redesign would make soviets batshit OP. I would like cons to be relevant late game from a design perspective but without changing other aspects of the game it would simply lead to more spam based strats.
The problem with grens is how prone they can be to squadwipes. Changing to five man squads will simply lead to more gren heavy builds which should be avoided. Relic have a problem in that grens need to scale well to compensate for the bullshit wipes but not so good that other ost units are irrelevant. The thing is if ost player is lucky rng wise and can keep squads alive then chances off winning are significantly improved. However should whole squads be lost early to morter strike, m3 flame car or mimes then ost is significantly behind. Other game mechanics being changed would be better than just adding an extra man.
Lastly grens not being able to build green cover is a major design flar. It may not have been necessary upon release but the game has changed since then and its omission is now stark.