Why is it important if it's "a language" or not? What we're talking about are concept representations (nouns), not languages. But I think most people who read "DALL-E has a secret language" probably picked up on that because we're accustomed to the hype in machine learning naming things to sound like they are more profound and powerful than they really are.
It's important if it's a "language" because the original thread claimed that it was one (and indeed, a number of comments in responses to this article are still making that claim). You may argue that discovering how DALL-E tries to map nonsense words to nouns is independently interesting, and that's fine (I don't find it interesting personally though--considering it has to pick something, and the evidence that these spaces are not particularly robust when confronted with far out of sample input, I don't even think calling it a secret vocabulary would be accurate), but the authors should reasonably expect some pushback if they argue that this is linguistics.
