Since Kings of Chaos is funded by advertising this could be seen as a disadvantage. Most of the adverts are not inappropriate and some universities use the site to promote courses which could be seen as a good thing. However some of the adverts are less suitable (for online dating for example) and discussing the pros and cons of falling for such adverts could become the focus of a lesson on web safety. In my experience and good ad blocker eliminates this problem in a school environment but you might only want to use this game with older students.
Some of the language in the forums is less than savoury but then students may well be subject to this sort of language when online in their own time. Again a topic for class discussion could well be about suitable
conduct and restraint in discussion forums.