If someone just says "AVX" they usually mean AVX(1). And that's what the article is discussing.

AVX-512 forking into tons of different beasts is a separate, but related, problem. But it's more like how SSE2, 3, 4, 4.1 and so on existed.

Sometimes people said "SSE" and they might have meant one the later versions, but I don't hear the same statement with AVX, since people very explicitly seem to say AVX2 and AVX512.