This has come up many times on other forums.
It is a good deal for Noritaki. VFD sales have plunged to zero, the vast factory cleared-out to make LED TVs or bamboo flooring; but they keep one machine rented to KORG and probably better terms than they ever got for oven displays.
It is a crappy vacuum tube. In audio we want enough current to shove stray capacitance around 5,000 times a second or faster. In displays, 10 changes per second is absurd, but great emphasis on Low Power. So these things are lamer than battery-radio tubes. (Which are very readily available, Golden-Age stock, at much lower prices than KORG is charging.) You *need* buffers in and out.
That said: you are gonna need lots of chips anyway to make a real product. So the small buffering the NuTube needs is trivial on the cost-sheet, especially compared to the market advantage of "Genuine Vacuum Tube Technology!!"
Anecdote: I once got a commercial tube channel, lot of chips and a 12AX7. Working without a schematic, I bypassed parts which I did not need. I made it sound a little better. On a later listen, I noted that it "warmed up" in 2 seconds, not 11 seconds. I had bypassed the tube! And was better off without it. (For that situation: dead-clean concert recording with inexperienced operators.)
