My best idea on what the whole canned sadness thing is thus,
If a product is free they are clearly getting profit from elsewhere…
They clearly have some kind of ties to whatever the index is, so they’re clearly some kind of divine….
And also the Ad thing did mention boredom…
So maybe the whole thing is basically a kind of entertainment for divine? Like you open the can, and deities watch you fight?
Well I guess that's not too far from how things are now - You've all been here for a good bit and seen your fair shares, so fighting wouldn't be too off the table. Not 100% on the profit angle still, but you're the detective here so you possibly know a great deal more than me in that field.
Regardless, whatever fights I pick with any of the sadnesses from the thing in there or the sample here will be on my terms, that much I can promise. I'd attempt a scrap with the sample now if I knew at least a bit more about the oh-so elusive "Claustrophobie" if there is any further info to garner, but I digress.