Yes it is...
Skeuomorphism is an aesthetic strategy for making software appear familiar or comfortable (or "retro" and stylish) by evoking parallel hardware/real-world solutions to the same problem. A console, on the other hand, is a way of interacting with software using typed commands.
An overlay for HN that presented it as a Renegade BBS instead of a series of web pages and web forms might be skeuomorphic, because that Renegade BBS interface would exist for aesthetic reasons only. But aesthetics aren't the reason you make a web SSH prompt look like a console.
That's the precise definition of skeuomorphism.
It's skeuomorphism not because it's a command line interface but because it's green and black, which is a nostalgia based design decision not a ux based one.
I can't remember exactly but there was some CRT based decision for earlier consoles to be green and black, that this console is aping it just screams skeuomorphism.
So CSS that emulates terminals / phosphor displays is still skeuomorphism - the definition mandates only that the design evoke older designs, not necessarily "real-world" designs.