Well, that is how they have been working for at least a couple of years so yes, “now”. Since you seem to think that the chest are not working, I assumed that you did not understand how they worked as there is a big difference between that and them actually not working which would be a whole different issue.

Since the bosses in the unnamed city already drop their randomly generated Legendary items I see no reason why the world bosses could not have the pool of random “key chest” legendary items added to them. So I am in agreement with your original suggesting and thus I did not feel the need to suggest anything else. :grin: