The one that hit hard was when they changed the exporters (I believe it was the change from 7 to 8). Documentation was limited, but it included gems reminding the reader that it's a lot of work to write documentation, but rest assured that it would eventually happen. Nothing was automated and frankly, I couldn't even figure out a non-automated way to update the files, as I could not find a replacement for some of the functionality I had been using.

Last time org syntax was changed that affected me, it did not do automatic conversion (it was just last release, actually).

In that case, however there was a code snippet to repair them. You have to know and read the changelogs for them though.