We have two spaces for project-wide communication:
The first technically is the responsibility of the Jupyter Media Strategy Working Group, while the second is nobody's formal responsibility.
We also have a community building working group with a mission of "growing, building, and connecting the Jupyter community of users and contributors".
Proposal
Ask the community building working group if they could accept responsibility for defining and executing strategy around these community spaces.
Rationale
I think that "community building strategy" is a more natural thing to drive these spaces than "media strategy" (which I understand as more external-facing). We use these internal spaces to make connections between people and subprojects, to be a space for users and maintainers to connect, etc. That feels like community strategy to me rather than media strategy.