What isn't clear is how this site actually violated that policy, if there was no course slot trading actually occurring. You could describe it as an attempt, but in this situation, the student asked for permission from the school before doing something that would violate their policies.
To use an analogy, if I sneak notes into an exam, that is likely academic misconduct. However, creating a formula sheet and asking the professor if I can use it is not academic misconduct. I wouldn't consider that to be attempted cheating.