I have read a lot of popular science and it often seems to gloss over a lot of issues. So I can't really comment till I've done some more reading.
But the cat in the box experiment drew me to some conclusions, and raised a lot of questions.
A summary of my thoughts (which can be thought to be completely wrong by those in the know, I am in my own belief box at the moment): follow.
For something to be as big as a cat described entirely by a quantum wave form, the box must be impenetrable to everything being emitted from inside. ie the box itself must undergo no measurable transformation what ever happens inside the box. This would have to include gravity as well if any quantum gravity theory would emit information depending on the result of the first nuclear breakdown.
So if two impenetrable boxes somehow become combined lets pick another word "entangled" then the wave form to a "wave form calculator" (not an observer yet) would now need to cover both internal states of the boxes.
And you are now back with the one box scenario (though in the case in the article there are now two observers).
However there always seems to be some confusion or glossing over what an observer actually is. It could be a particle or some people even seem to suggest that it needs a conciosuness, but I think that is a bit of a stretch. I consider an observer to be anything that is instantaneously interacting with an object described by a wave form from it's point of view, as soon as it does this it has become part of the wave form from another external observer. But it now has special knowledge of the internal state of the wave form. Effectively it has "climbed in the box".
On a cosmic scale this seems to indicate that the parts of the universe that are beyond where light can travel from by now (due to expansion of the universe) are in one massive wave form, Until a single photon leaks out to give information about a past state of the wave form. The wave form collapses and a new wave form is born.
If there really is a dispute about what is in the box after two observers have measured it, then there really is something weird going on, as it would have to mean that quantum entanglement is partially broken, which would then solve the a paradox as the two boxes would appear to have but never entirely entangled themselves.
No doubt the many worlds interpretation may say that the combined boxes are from two "different worlds" so that they can give inconsistent results when individually measured.
My 2 pence worth. But I know I am wrong about a lot of the details here.