
No, they don't say otherwise. For one, the LN never says she's a loli by definition. Neither does the author. What you're referring to here is the running gag, because she's small. As an insult, or a
->JOKE<-. It's called comedy. Did you forget Megumin and Yunyun are literal classmates?
They're teasing her due to her petite body. It's why she gets mad when they call her one. Because she isn't one. I can give you a fuckload of examples of other anime where this exact teasing trope is in, with characters that aren't lolis. You think them teasing Hestia by calling her an oppai loli means she's a loli? A busty, buxom goddess with a fat ass who is simply short, is somehow a loli because any time the word is mentioned, regardless of context... it's a literal interpretation? Nice meme.
Cool strawman. Every one of those are lolis. That doesn't somehow mean every petite girl that is flat is also one.
Which is literally what megumin is, a petite flat girl with chest insecurities. It's both a body type and a personality. Your point? You looked up what it is, but you forgot to apply it to the context, or didn't understand why I mentioned it- which is bizarre as it's pretty clear cut.
Once more, Celia is not a loli. Pipi is. And the difference between them should be obvious. That you think they're the same thing is ridiculous. Saber from FSN has the same body as Celia. So in your head, Saber is a loli? Be real. Look, I can
maybe concede in good faith that megumin is pretty fucking borderline, especially due to her age at the start of the show, less so towards the end. But most Japanese do not consider her a loli. The opposite (to a degree), with westerners, because normies and the mainstreamification of anime. Everything is beginning to lose meaning such that there's only big tiddy=milfs and flat=loli and nothing in-between. I get that it's a losing battle for people who actually know any better. But your attempt to gaslight anybody into thinking Celia and Pipi are the same is completely out of touch. Saber and Kanna aren't the same thing. To suggest otherwise is pure cope.