Surely they had the foresight to plan for eventually size increase for Nobs ... right?

I hope so, but then the nobz would need a stat boost(health, strenght and toughness) because of bigger hitboxes.
But if that happens then the other factions would whine about it.
I already see it: "Nobz to OP, plz nerf".
Then some of us would be like: but it's in the lore bla bla bla and so on.

I wonder if SM fan boys would even support that claim because of the obvious
future balancing issues.

Plus dont forget there are very few players streaming the games when they are playing as orks.

Entirely possible with the precedent. They recently buffed most all Veterans armor levels.

'ere 're me Nobz!
Da Slugga

An' me shoota