The question of whether Pluto should be removed from the list of planets, and moved to the list of "minor planets" began to be discussed in the 1990's, and reached the newspapers around 2005. But there had been some related discussion decades earlier. In the August 1956 issue of Galaxy Science Fiction (pp.79-91), the science fact column, "For Your Information" by Willy Ley, began:
I can't make up my mind at the moment whether the charge that it is a former moon that managed to make itself independent should be considered detrimental to its reputation or whether that should enhance it. But if you take the position that being a runaway moon instead of a born planet is a demotion, you may add that the demotion is richly deserved. ...
The remainder of the article leaves this "what to think about it" question behind, and is a well-written review of the history of the discovery of Pluto, the peculiarities of its orbit and its size, etc.. (I like the style better than the hype of modern science-journalism.)
Incidentally, in saying, above, that Pluto is "technically a planet, since it moves around the Sun in a closed orbit", Ley is evidently comparing it with moons, not thinking about the fact that asteroids also have closed orbits around the sun, as do many comets, though neither are considered planets. Present-day discussions of the question relate Pluto to Kuiper-belt objects. It is interesting that the person Ley quotes is presumably the one after whom that belt is named. (Of course, I ought to search out Kuiper's article, rather than just quoting this note that takes off from it.)