And you're wrong. Look at any potential changes vs actual changes. They're almost always different. I can only think of 1 age where the potential changes didn't really get altered.
The only thing that's "locked" are the large, usually mechanical, changes. This age for instance, it doesn't matter how stupid people might think the overall number boosts might be, that's a thing that's going to happen because it would require a complete overhaul of the potential changes.