In addition to what @hackscribble already wrote:
There is also the courtyard layer. The intention is that the courtyard layer is designed such that it enforces the space needed for a pick and place robot.
Or if you assemble your boards yourself the space needed for the solder iron. But in this case it might be necessary to enlarge the courtyard for some footprints. The only problem is that there is not yet any automatic check for courtyard overlap violations.
Also note that any official library is a compromise. It is designed with "one size fits most" mentality. (Some would say: "one size fits nobody".) In other words: Check if the footprints you use fulfill your requirements. And if necessary create your own "approved" library that fits your needs. (The official library might be a good starting point.)
If you find footprints that do not follow the new klc it would be nice if you could not only change them for your use but share them with all of us by creating a pull request on the official library. (This only applies if the klc fits your needs or if you are prepared to do extra work.)