I found something similar a while ago where I realized that the MA page for the Mirror Universe version of the Federation had been called "Terran Empire" for something like a year before that term was canonized by "In a Mirror, Darkly" (before then, it had just been "the Empire" when it came up in episodes). That probably wasn't from Memory Alpha, though, since the name "Terran Empire" had already been used by Judith & Garfield Reeves-Stevens in their novels, and they worked on that season of Enterprise.Side note, funny thing about that.
One of the Memory-Alpha pages talking about the Klingon Great Houses had mentioned '24 Great Houses' from almost the very beginning of the site's existence and no one bothered to fact check it. It wasn't until a few months before Discovery's airing that I decided to find the canon source for that that claim.. and couldn't, there wasn't one. I pointed it out and it was promptly removed from the page (and then added back again once Discovery aired)
Maybe the Discovery writers got it from that error on M-A lol
Now I'm curious about the original provenance of the "24 houses" thing. It seems to be Google-proofed thanks to Discovery. Maybe a novel? RPG sourcebook? Or just some overzealous editor adding some fannish embellishment (or maybe counting the chairs in High Council scenes in TNG/DS9)?