A little bird told me that a certain homicidal demigod confirmed this rumor as fact.
An EM event has just this minute finished on Europa, and Fynn Barrett (The EMs character), after we'd explored Exodus to look officially at the Nexus', and I'd confessed I'd not just taken one but sold a few on, asked us to get the co-ordinates of all the Nexus' taken out of the dungeon, and to not take any more out... those things are dangerous!
Out of character, I asked if this was a roleplayed issue, or were they locating and recalling the items because of a potential bug...? Because I didn't want to declare the location of other people's Nexus' that weren't interested in roleplaying the arc itself. Also Nimauq asked if he could confirm whether the spawning was intentional? The EM stated it was just roleplay and not to worry about tracking down the ones I'd sold, but wouldn't confirm what the Nexus were supposed to be doing.
Which means, reading between the lines, they probably are supposed to spawn, and for arc related reasons...
I have to admit, it's a sudden tonal shift, from encouraging mindless grinding just for loot, to turning our looting against us in the name of wider story telling. But I suppose there is warning of this shift in that the person who sends us to do so sends us to somewhere clearly dubious (Exodus Dungeon) and is himself a right shady character. So if this is the case, then it will depend on how well the EMs can link this into their own narratives. The ones on Europa seem to be doing it well so far, and my main character now feels very guilty indeed, normally virtuous, but the idea of making a little home improvement cash from what could, if you didn't think too deeply about it, seem perfectly harmless...