Connections at that level don't mean a lot because sitting on the same philanthropy boards is a form of networking, it'd be like finding them on the same Discord server, in terms of significance and the number of links you could make that way.
Of course, but both Toner and McCauley are on the same boards with the same handful of organizations (Centre for Governance of AI, Centre for Effective Altruism, OpenAI) and Toner (and her coworkers/managers like former OpenAI Board Member Holden Karnofsky) both managed grantmaking from OpenPhilanthropy to the organizations above. If you're working together in that many organizations you will end up having a working relationship.