After discussion with the runtime team, we believe that it is reasonable to add an additional warning note to the description of -Xnoclassgc. This is not a final recommendation, but we could do something like this:

OLD:

  -Xnoclassgc
      Disable class garbage collection.

NEW:

  -Xnoclassgc
      Disable class garbage collection. Use of this option will
      prevent memory recovery from loaded classes thus increasing
      overall memory usage. This could cause OutOfMemoryError to be
      thrown in some applications.