Well, I will update this thread tomorrow with further legal proof, but waivers, especially 'blanket' waivers, like these, are interpretable and not in any way bulletproof.
A level of protection, yes, but not protection complete.
Without being braggy, I have a level of certainty and by proxy, expertise in this narrow regard (and I mean as narrow as possible - just asked a lot of lawyers) and it has interested me in the past and I've asked a lot of people/researched this.
Furthermore, I missed this upon first read, but you say 'AA wouldn't have any games', well, the reason that AA games don't have any drama is because they ARE 18+ and people are responsible and honorable and are willing to reap the consequences of their actions. There haven't been any SERIOUS injuries to my knowledge, but the ones that are semi grievous have not seen the light of a court because the ones so effected know that it's their fault, and they deal.