The language thing is just that without writing, reconstructions based on regular sound correspondences only allow us to infer backwards by a few thousand years. It doesn't mean that anything particularly interesting happened exactly at that time to human language. It's just that language changes relatively fast on this timescale so current languages don't offer enough clues.

And the origins of language are famously uncertain. Might have been recent and relatively sudden (<100 thousand years ago) or a gradual slope for many hundreds of thousands of years.