Decided to finally get an account and post here.
This (the 16 current Shardholders killed Adonalsium) was, in my opinion, the greatest revelation in the two books that just came out. It puts a lot of things into perspective. Some quick thoughts:
1. God-killing, of course, is not necessarily an evil act by itself. Khriss mentions a multitude of motives, and we know that there are individuals among the Shardholders who were decent/honorable etc....
2. Whatever were the underlying reasons for doing what they did, the Shattering hardly stabilized the situation.
3. Ym's belief system may need some additional in-depth study. I am now certain that this was a decent-sized hint as to various motivations.
4. It seems that whatever the end-game is for Cosmere in its current form, survival of any Shards may not be necessary or even desirable. I kind of like the idea that Hoid's plan involves making sure that all Shards are down at the end, and their powers are scattered around Cosmere.
5. I too am very interested in whatever transpired between Hoid and the 16 Shardholders. Was any of this in Dragonsteel Prime?
6. Finally, we learned that you cannot take a Shard without establishing some sort of Connection to it. So, how did this play out at the Shattering? Did Adonalsium Shatter into these specific Intents because the 16 had Connections specifically to them?