IMO the single biggest risk to the fediverse is allowing one instance to control everything. I think there needs to be a set of ideologies that all fediverse users agree to abide by for the good of the fediverse, the first of which would be: instances should not federate with other instances that are too big. I don’t think “too big” needs to be strictly defined, it could be left up to people to decide, but if users or other instances think you’re idea of “too big” is too big, they are all free to leave/defederate from you too.

Idk anything about Flipboard, much less how many users they have, but if it’s much larger than existing servers, then I think they should make an effort to shrink, or at least freeze signups, or be defederated.

Also yes, I think mastodon.social and lemmy.world are too big and should make an effort to downsize asap.