No, this is no longer what these terms mean in common parlance.
(There is no arbiter of language; words are imbued with meaning through usage. People use "first world" and "third world" quite differently now than during the Cold War.)
These words are no longer used in common parlance at all.
Now people use "developing nation" and "developed nation," and "second world" never evolved to mean "somewhere less poor than dirt-floor huts but less rich than London". About once a year I see someone make that mistake; it's not common, just a mistake.
But agreed, there's no arbiter of language for English, and we all understood the original poster, which is really the important part.
> These words are no longer used in common parlance at all.
> it's not common, just a mistake.
What's the difference between "common use" and "mistaken use" exactly? I've heard phrases like "third-world [pejorative]" thrown around here and there over the years. Is that a mistake or a change in common use over time?
First/second/third world stopped being used by academics and journalists, oh gosh, maybe a decade or two ago? After the fall of the Soviet union, but I don't remember how long after. Developed/developing nation replaced them.
As someone else pointed out, "second world" always referred to the Eastern Bloc countries (the soviet states and those allied with them). It never meant "somewhere in between first and third world, in terms of quality of life". That's the mistake.
The language shift was from first/second/third world to developed/developing nation, the mistake is using second world to mean something other than an eastern bloc country; you'd probably be understood, but that meaning was not ever in widespread use.
Literally once every 4 or 5 years I've heard a layman say "second world" referring to "poorer than America, richer than Ethiopia"; the lay usage is probably still first/third world, but people are slowly cottoning onto developed/developing nation.
I think even in common use, that use of "second world" is still "wrong," as far as anything in English can be wrong. Ted Cruz referred to it as a "basketball ring" and we all had a laugh, but we also all understood what he was talking about; is that wrong?
I'm mostly reluctant to tell anyone that their use of English is wrong, because it's such a fluid and ever-changing language; but when something like "second world" comes up and not in reference to the Soviet countries, it still jumps out at me as "well, that's not how people always used to use that phrase"...
It was invented in the 50s in france and literally is translated to 1/3rd world (tiers monde.) third (as in third place) would translate to troisieme. Poor translation basically.
(There is no arbiter of language; words are imbued with meaning through usage. People use "first world" and "third world" quite differently now than during the Cold War.)