I live in the UK, but am from Norway. I know a few librarians though, and I know that community libraries are usually (or at least often) interested in projects that can connect their communities and help them with outreach. Something like this certainly could do that, and with libraries existing in most communities there is a built in network for broader proliferation there.
I’m also just very keen on the idea of libraries having a central role to play in the future of the broader fediverse ecosystem.
Edit: It may be key to pitch this to them not as a platform, but as a decentralised community network.
So I’m guessing it’s a combination of dun/den/tun etc being a common suffix in a lot of historical languages, and ‘ei’ being an extremely common diphthong worldwide just… leading to a lot of similar-sounding names that also converge in spelling in modern English?