Kyle:
When they blow up original golf holes to build a practice facility, or to expand the clubhouse, that is pretty much a permanent decision that isn't going to be restored later. [It's feasable to blow up the practice facility and restore the holes, but I've seen at least 15 cases where it ought to be done, and it never has.]
Obviously, too, if some of the course is sold off for housing, that's it.
The other issue is when holes are changed for safety concerns, either by planting of trees or by moving the hole away from the boundary. There's no going back there.