Nice article Kevin! I'd disagree with this point. For example, how do you outrank Wikipedia with your WordPress blog? The answer: you can't. Google's PageRank algorithm is based on links from other sites to your site. So unless your site is going to get millions of links to your domain, like Medium or Wikipedia, then it's going to be hard to outrank the same content at Medium.
You can get both benefits by cross-posting to both places, then pointing the "Canonical URL" at Medium to your own blog. That tells search engines that your blog is what they should rank, not Medium, but theoretically you'll still get the search benefit of the content being at Medium.
I'd share that I often get 90-97% external views, and those views don't pay for 2 reasons: 1) they're not Medium members and 2) Google AMP means there's no quota for searchers on mobile devices. NYTimes is a similar situation: you can always bypass the paywall on mobile because of their AMP setup. On the flip side, AMP means better search ranking because of page speed.
You do get paid if someone who wasn't a Medium member signs up in that month after they already read your article, though.
But to maximize earnings from the Medium Partner Program you need to focus on going viral inside the platform, including getting distributed (curated). SEO really doesn't matter if your focus is on Medium earnings, as I'll discuss in my upcoming SEO guide.