I think the focus on the technical difference of push vs. pull ignores the way that a push vs. pull mindset affects the content. A newsletter author expects the

I think the focus on the technical difference of push vs. pull ignores the way that a push vs. pull mindset affects the content. A newsletter author expects the same audience (more or less) for each post, and so can build up a common shared context with the audience (as, e.g., Matt Levine does with recurring themes like "should index funds be illegal"). With blogs you generally write such that someone who landed from a search engine can dive right in.