This analogy keeps being made but I am not convinced it is correct.

Any participant in a dynamic network can choose with whom to have relationships. That's the point of a firewall or cloudflare or a million other security efforts.... to prevent interactions which due to malice or accident would cause some harm to come to the local system. There is no obligation to participate and in fact with the fediverse it is specifically designed with defederation in mind.

The comparison has been made to email explaining the fediverse concept to new users. Most people know about email. But Usenet is much more apt, if you are familiar with that. Usenet had (has) similar concepts such as the way servers share, mirror and distribute content from others servers. There is a burden imposed on any given server according to the others it has communication with. If you never had the pleasure of being on Usenet, it was basically like email discussion lists where the inbox was public. But you still needed to have access to a server to read and post. Messages were sent in similar way to email but every server would retain a copy of messages prior to forwarding them on to a list of other servers. They would in this was percolate through the network. Every server had its own version of the history of usenet according to the choices of the admins and there was not central authority or main copy.

Usenet server admins exercised broad discretion deciding who they would have a relationship with and what they would accept. Nobody was every perfectly connected to everybody else for various reasons including: legality, morals, politics, technical, geography, taste and happenstance. Individual people, hosts that allowed too many bad users, problem communities, filetypes, topics of conversation.... all kinds of things were blocked by admins. Some news servers were permissive and some were restrictive. Servers that were excessively permissive became hubs of spam, and thereby risked losing their relationships with other servers because other admins got too annoyed having to deal with it. And servers that were excessively restrictive had a hard time keeping users because you couldn't really participate properly if unable to see a lot of groups and not seeing a lot of the traffic, plus your messages would not propagate for others to see. So it was a balancing act.

For the most part this is an analogy that isn't helpful for a lot of people.. But maybe on SDF there are some who can recall those days. I do not think the concept of blocking servers breaks the concept of the fediverse at all.

(I am still undecided on my opinion on the question but I think it is a legitimate possibility.)