"the company looked at the history of social media over the past decade and didn’t like what it saw… existing companies that are only model motivated by profit and just insane user growth, and are willing to tolerate and amplify really toxic content because it looks like engagement… "
Specifically, the model should be the Wikimedia Foundation. That is, a non-profit organization with lots of stakeholders and slow procedures to guarantee accountability, and lots of resources to guarantee it won't go away. This is the pragmatic least-bad solution to the problem of centralization on the internet.
Wikipedia Foundation is also bloated and unfocused outside of their mainstay product. But like Mozilla, they generally do good with the bloat and unfocused resources. Inefficiencies are easy to identify but hard to mitigate.
Yes, bloat and mission creep is going to be an issue with any big non-profit. But maybe that's also their advantage: any organization that becomes focused on sustaining itself is going to provide decent long-term stability. I guess it's a bit like a state.