I could see arguing here with myself that AAA games are usually "ship and forget", with some bugfixes only. Maybe because company I was working in was not AAA, but small (by industry standards) f2p mobile shop, where applying AAA ideas is not that great (in my opinion). I mean that's where your product is more along lines of web apps - you are going to constantly add content, update code base, refine features, so focusing on quality in long term is better. This, thought, I was not able to articulate clearly and properly to AAA veterans.
I feel like not all ideas from current practises can be applied to big gaming studios, but saying that I believe it can be improved. This may need time and risk that companies that are big enough to be called AAA are not willing to take.
Why two companies you mentioned failed? I think we can assume there might be more reasons to that than only being Agile, maybe their games were just not that good, or IP was boring? Still you sound like you have more experience than me here, I'm trying to wrap my head around whole AAA industry thing. I'm ranting about it so much because making games was way more entertaining than web/mobile, but the industry is so poisonous for pure developers that I had to quit to regain my sanity :)