This new Semantic Search is(still) just about relevance and quality. I've said it countless times, and I will say it again - Google has always been about providing the most relevant results to people using their search engine.
That is how they keep the majority of the market share which in turn gives them more money from their advertising platforms.
To be honest, this is really nothing new. Google has been trying to get their algorithm to the point where it can "think" more like a human would for years. That is why they are continually testing new changes to their algorithm and collecting data on those changes.
It looks like maybe they finally have collected enough data to validate a change in their algorithm, but if you have high-quality websites that are relevant to their targeted niche/topic(not an EMD with a few pages of similar KW-targeted content), I don't think you will have too much to worry about.