In terms of open education, I think there is much to like about how the fediverse operates.
At the OER level, federation is one way to get around the desire for the “one repository to rule them all” approach. Standards-compliant, federated repositories (think Peertube for video) that are connected via federation allows discovery tools to be built that could easily search the fediverse for relevant content & aid in findability while allowing local control of individual repositories to be at the local level. No need to support a behemoth of a repo when a thousand small scale repo projects can be connected together.
In terms of open pedagogy, having a local, locked-down instance of a platform can give learners some confidence to work in a safe controlled space and, as they gain confidence and skills, can then be connected to a wider ecosystem to make their work or conversations more open. Think a local Mastodon instance for a course that stays local for the first 6 weeks of a course while learners find their feet, and then opens up to connect to the wider network for the final 6 weeks of a course creating a hybrid closed/open pedagogy model.
Really, what federation is about is resilience & sustainability. Federation is the overarching design feature of the most resilient of all networks - the internet - and embracing federation is embracing resiliency in design. One node falls, other nodes are still there. And having that broadly distributed network baked into the systems we use could be a key to open education sustainability.