Kyle:
Thanks for posting this. It's a topic I have underestimated in my work on golf courses, partly because when we are doing restorations we don't have any reliable 3-D information about the original greens, and partly because most clubs are loathe to tear up the greens in a renovation unless absolutely necessary [because it involves closing the course].
However, I have often looked at a green on an old course and had the feeling that the contours had changed over time, whether by deliberate action or not. And I've actually witnessed changes over time at Crystal Downs [which I've known for 30 years] and at Pacific Dunes [where the wind tends to topdress certain greens very unevenly, especially #14], so I'm starting to realize that it happens more often than not.
The biggest factor to me in recent years is the USGA's recommendation of heavy sand topdressing for greens on older courses. At Crystal Downs, this program over 30 years has built up the green surfaces [and importantly, only the green surfaces] 4 to 8 inches from the grade I knew in 1986. As a result, greens that fell front to back now have a bit of a rise in front of them that makes the running play much harder; the falloffs at the low sides of the greens are much more severe; and some places where there was a subtle "dish" in the green are now just bald plateaus. I've observed the same evidence of evolution at Cypress Point, SFGC, and other clubs where we consult.
But what to do about it? I can't see any way to restore the old green contours; you just have to rely on an architect you really trust.
Mike Y: I have seen only one instance of one of my greens settling over the past 25 years of construction [the left front of the 3rd at Stonewall Old]. But we generally don't build greens out of fill material, so my experience may be the exception rather than the rule.