The lack of details makes me think they're either hiding a new technique they'd rather keep secret because it provides a competitive advantage, or that it's really only a marginal improvement over existing NLP models (or an ensemble of them with nearly no improvement on any given metric) and the 1000x improvement is on a metric that no actual ML scientist would respect.
I don't have the slightest bit of information about Google's AI team to know if those are the only two options and if so which is more likely.