No, because think about it. An imageboard has increasing post numbers, and how would that be incorporated between multiple sites? Who's going to keep track of what post number the whole system is on? And if different sites track them individually, then how would posts be copied between sites? if the post numbers overlapped then which would take precedence? and if you change all the post numbers it would break all the links as well, correcting that on one site is a bitch, imagine correcting it on a dozen.
Maybe if instead of a No.# it used some sort of hashing/consistent hashing, but then it wouldn't look the same. How would cross-site linking work? Maybe it would have to prefix a domain, like >>>>org.leftypol.1234 or something? but then that would totally change the way links look, not to mention involve an ungodly level of cross domain image loading on the hover thumbnails, etc.
plus there's the fact that most imageboards have extremely edgy content and wouldn't want to necessarily trust another site enough to be in a ring with them, seeour situation with getchan and how they turned out to be pedos
and we were only in a webring with them, imagine if getchan and .org had been federated or something.
The technical aspects of making a federated or general distributed system would fundamentally alter the nature of what an imageboard actually is and how it even looks.
In my experience people generally underestimate the difficulty involved in making truly distributed systems with no central authority, just thinking about it for a moment will bring up all kinds of challenges/design decisions which no one has even begun to think of.
All these "muh federation" guys should literally be forced to read a book on distributed systems before spouting off about how its superior. I've attached one here. Tannenbaums books is also good if you can get it