It's a very deliberate phrasing, since not everyone agrees that initialisms are not acronyms.

Personally I think that "ackhually that's an initialism not an acronym 🤓" is exactly the kind of ultimately irrelevant distinction that internet know-it-alls love to know and point out. I know because I used to be like that too when I was younger.

But often those distinctions are not universally acknowledged or useful in all contexts. Like how strawberries are not scientifically berries, but we still often group them as berries.

Nitpicking word definitions is pointless when the distinction being pointed out is not relevant for the conversation.