Apparently, this is the second octopus city discovered, which is interesting -- they're exhibiting more complex social behaviors.
However, I have two complaints.
A lot of the stories are describing Octopolis/Octlantis as "gloomy". Why? Is it because the inhabitants aren't swimming around with toothy grins? The cephalopods look quite normal to me.
A more serious complaint, about this quote:
The discovery was a surprise, Scheel told Quartz. “These behaviors are the product of natural selection, and may be remarkably similar to vertebrate complex social behavior. This suggests that when the right conditions occur, evolution may produce very similar outcomes in diverse groups of organisms.”
Nope. You don't know that. There's no evidence and no reason to think this behavior is the product of natural selection -- quite the opposite, actually. It looks to me like the spontaneous emergence of a novel property of octopus behavior in an unusual and fortuitous environment.