It appears that Yoast founder Joost de Valk and Yoast’s current CEO Marieke van de Rakt have a stake in WordProof, which is building a Timestamp Ecosystem that will support multiple blockchains to verify online content.
Wordproof explains the SEO angle: “timestamping content on the internet combined with search engine optimization” creates “opportunities to fight fake news and fraud on the internet.” ☑️