Sure, but if I'm thinking along the same lines as the OP, is all of the content truly new or different? Or is there a lot of redundant data in those updates?
If the game is 55GB, and the update is 55GB, and the game remains 55GB after the update.... ^.^
But if it's a 600GB game? Well then dunno. But I don't think any game has reached there yet... CoD is getting closer though