Think it’s true. At the beginning AMP pages got a huge rank bonus. Now, it’s much less. I feel Google sees AMP just for news pages. Guess the project got a lot resistance internally which is understandable: With the hundreds custom AMP components they are actually rebuilding the web.
That they ever got such a thing is ridiculous to begin with. One of Google's principles is that they're neutral, besides clearly labeled paid-for ads which have always been the business model. I don't think they succeed 100% in setting aside unconscious biases that the programmers must have that build and tweak/configure the thing, but I believe that it is one of the basic ideas. If you say that was not the case, and is "much less" not the case now, then saying it's not biased is just weird.
http://www.benedelman.org/adlabeling/google-colors-oct2014.h...
I don’t like the entire AMP thing either but a bit more differentiation would be helpful here.