I believe why they're calling it a "new phase of matter" is because the electron-pairing is remaining at temperatures it is not known to have. IMO this sounds

I believe why they're calling it a "new phase of matter" is because the electron-pairing is remaining at temperatures it is not known to have. IMO this sounds more like there is a required energy level for electrons to actually be singular in their orbits and that at superconducting temperatures the electrons degenerate into electron-pairs. The structure of the cuperates must increase the energy required for the electrons to sustain being singular. I don't think it's likely to be a new phase of matter, but rather an exploited special circumstance.