@tim tbh, I don't know exactly the relationship. The primary developer was at WP Engine and they sponsored his time working on it (afaik). I don't know if they, themselves, were maintainers, etc.
But yeah, Jason is moving to a8c from WPE. As he says in the linked post "While [WPE] has treated me well personally, the focus on open-source contributions from the organization has declined during my time there. My time was also reallocated away from WPGraphQL…as internal initiatives took priority."