Good SEO comes from sources like search engine documentation, ideas from experts, up-to-date technology news & broad marketing knowledge.
Google’s API leak, while interesting, shouldn’t have revealed anything totally new for SEOs.
Some SEO recommendations, like non-branded keywords in titles, almost always help. Others like how to update internal links aren’t clear. Over-optimization is real unfortunately.
The best approach then is SEO testing. This means comparing similar pages, not variations of the same page. Large sites have an advantage, but you can do split tests on a smaller scale too.
With machine learning & user data affecting search rankings, it’s impossible to know best practices for certain. However, you need someone that knows the right inputs.
This ever-changing state also makes SEO unpredictable. Why pursue it then? Because organic search can have tremendous ROI.
Without SEO, other specialists understandably give little thought to it. Involving SEO though has campaigns achieve far more “along the way.”