I'm nitpicking just a little, but isn't discovery always about something unprecedented? Otherwise it's not that different from the rest of the scientific work people do.
As a disclosure, I'm a physicist, having worked on quantum computing during my PhD. I think it's really cool, though long qubit lifetime doesn't take you far, the devil is in the details, for example good (reliable, low noise and tunable) qubit-qubit interaction (how in this case?), and reproducible devices (not at all in this case, every diamond will be different).
I think a discovery that improves the storage time of qubits by 6 orders of magnitude is unprecedented. Also, even if this technique has terrible qubit-qubit interaction properties, it would still be useful for storage. You could just read the qubit out, do computation in a different medium, and store the result back.
As a disclosure, I'm a physicist, having worked on quantum computing during my PhD. I think it's really cool, though long qubit lifetime doesn't take you far, the devil is in the details, for example good (reliable, low noise and tunable) qubit-qubit interaction (how in this case?), and reproducible devices (not at all in this case, every diamond will be different).