How is a very elaborate blog post indicating the what & why considered marketing?

In my opinion this goes WAY beyond the usual changelog entry in other repositories.

Don't get me wrong, this is great documentation, very high quality, and well done to the React team for a great release and what I think is a solid decision around what to include and what not to include in this release.

I think it's important to understand though that React is _marketed_, and unfortunately for many a name as clearly stated as this will likely define their expectations significantly. This could be especially pronounced for those who are less proficient in English.