Well, yeah, but that's all analogous to a chaotic city on the Material Plane. This is the Epitome of Chaos. This spurns Order by it's very definition, and order is one of the defining characteristics of a city, as I understand the term.
Just having agreed upon rules for how everyone can exist close together, a system to exchange goods that are produced, and the distribution and claims on property/posessions strike me as bare minimum for an urban environment. How do you do that with Slaad for neighbors?
It's true, I may indeed be close minded, in that it's outside my comprehension. Perhaps another person can imagine a structure that works. I'm willing to admit limited thinking and ignorance.
Okay, now you're just too hard on yourself. I fancy myself an expert on alignment, as you know. And I can tell you're right. Ultimate entropy should not change no matter what you do. But here's the thing: Neither Limbo or the Abyss is the
Epitome of Chaos - that's
outside the Abyss. Both can be shaped and permanently so, but the intelligent essence beyond the Infinite Layers bows to no one, not for a moment. It's incomprehensible and entropic to the point where Demons themselves run for their lives when they so much as catch a glimpse of it. A
mere imitation shreds a weak will into rags. Ironically, that pure entropy is what also makes Demons predictable, while we can never know for sure what a Slaad or a Githzerai is up to.
You are forgiven to think that Limbo is the source of ultimate Chaos, but not only it never was, it didn't even exist yet when Chaos already thrived some planes downwards(that's not it's first source, by the way). Chaos in pure form is always tainted by evil, just as law in pure form is always tainted by good. It's their natural state, because to them, morality doesn't exists. Law came to be for the betterment of the world of D&D, while chaos can only destroy. These are respectively the only things they should be capable of. CG a LE people only twist them to their purposes. First, out of chaos spawns order by chance; imposed order brings the concept of compassion, order is corrupted by malice, and goodwill turns to freedom to oppose it, as it is written in the Pact(at least belief says so, and belief is the neutronium golem in the playground).
Thus Chaotic Neutral planes and creatures are not the epitomes(the black slaad description's writer was a little hazy on the origins of the cozmology), they are tempered with a conscience, or at least, in the slaadi's case, enough apathy for destruction to not do it all the time. They are not allergic to order and goodness(which is normally orderly) like demons are, because they don't feel the need to destroy what they oppose driven by their chaotic nature. Slaadi don't
have a nature. The absence of it makes them Chaotic by proxy. They don't feel the need for anything. They do what they please, their opinions and decisions unnaffected by peer pressure or other's will, as the phantasmal magics, the will of the people who want them to be what they are, that spawned the Outer Planes(and by extension, the Slaadi) protect them from both. They are basically what chaos would be if we forced it into a vacuum.
In short, if they want a city, they will damn well build a city, and they are
so chaotic, they won't give a damn when you tell them chaotics weren't supposed to do orderly stuff.