Like...? You always talk in vague generalities and never actually provide examples. What. Other. Games?
That's...not how iteration actually works in development. You feature lock early and usually don't make major changes once that's done as those are fairly fundamental pieces of tech to the game overall, and you work towards content lock. At that point you spend time polishing, because polish work done prior is largely a big potential waste. Things are still cut and added throughout content locking, so if you spent a week polishing something that gets cut later on when you're locking content then congrats, that's a week of multiple peoples time burned and wasted.
I don't know why you and others keep talking about CIG's development as if it's "standard" while also talking up how unique it is. Nothing about CIG's development process is remotely "standard" in game development and that's the whole reason there's so much ongoing discussion about it. Because they're not operating like any other development studio operates or following traditional/best-practices for gamedev.
The entire development timeline for those games is irrelevant to the polish timeline for SQ42. Unless you can show that both games were "complete" and spent years being polished.
Again, this is not how game development works anywhere else.
Those are all examples of content cut because they didn't have time/budget to complete them for launch, or that got far along and simply didn't work out. It happens, but this is, again, not as "super common" as you say it is.
So...was Chris lying when said that the game was greyboxed and in the polish state after that news came out then? Or is there some weird time travel shit going on?