The author of the Bloomberg story added on Twitter that the AI in RankBrain does not run in real time and is rather trained periodically.
In other words – he learns.

The AI took about a year to develop. It’s now carefully baked into the engine’s core algorithm to handle about 15% of the queries Google receives.
But what happens when Google gets bad queries? Some webmasters speculate about an increase in zombie traffic, which was the subject of much heated discussion in 2015.
Either way, SEO is constantly changing and old tricks may not be enough in 2016. Expect to see lessons and results from the bigger brands that generate higher traffic, and expect the smaller players in the market to catch up with them throughout the year.