It's just, calling language emergent sounds close to the view that you have to whisper furtively when you get too close to MIT: that maybe there was no evolutionary event that created language at all, it's just a really good meme[1] that makes use of other faculties that already existed in the human brain.

Maybe universal grammar isn't a physical fact about the possible ways the human brain can communicate, it's just that if we observe 6,000 variations on an idea with the same[2] origin and try hard enough to sum them up, we'll succeed.

[1] In the original sense.

[2] Or similar origins. Maybe language is a good enough idea to arise multiple times and converge, much like eyes. And I'm not sure whether to count things like Nicaraguan Sign Language as a separate origin of language.