I'm curious how they built this. It's SSH but the IP address is Cloudflare's edge network. It could be using CF Tunnel to transparently route all the SSH sessions to some serving infrastructure, but I didn't know you could publicly serve arbitrary TCP ports like that.
Building it in serverless fashion on CF Workers would be ideal for scalability, but those don't accept incoming TCP connections.
Cloudflare Tunnels only open HTTP/S to the internet, you'll need their client to reach the other protocols. More likely that this is Cloudflare Spectrum.
Some protocols do not support virtual hosting; apparently this includes SSH.
It would be possible to support other protocols with a single IP address (either because they are running on the same computer, or for any other reason) if they support virtual hosting.
Of the "small web" protocols: Gopher and Nex do not support virtual hosting; Gemini, Spartan, and Scorpion do support virtual hosting. (Note that Scorpion protocol also has a type I request for interactive use.)
NNTP does not support virtual hosting although depending on what you are doing, it might not be necessary, although all of the newsgroups will always be available regardless of what host name you use (which requires that distinct newsgroups do not have the same names). This is also true of IRC and SMTP.
However, if you are connecting with TLS then it is possible to use SNI to specify the host name, even if the underlying protocol does not implement it.
(This will be possible without the client requiring special software, if the protocol is one that supports virtual hosting. There may be others that I have not mentioned above, too.)
