Personal, I don't think Grimblight is ever going rare. Just by what the Devs have said. They haven't said anything about it.
I do remember them saying the Chaos War was bugged and whatnot and were going to fix it and release it. I don't know if they are still doing that or not. Try asking Artix, Alina, not Cysero, or one of the AQW Q&A devs on Twitter.
Um, the Design Notes on the main site showed a picture of J6's chess set. I don't know if they are going in Quibble's shop or are going in a personal Artist shop.
Hope this helped.