In an interview Sony gave to AV Watch recently, the company admitted it's going to "gradually end development and production" of recordable Blu-rays and other optical disc...
This is more akin to when Sony decided to stop making floppy disks. The market is there for now, but it’s just not worth it from a financial perspective.
Ironically Japan is just now phasing out floppies, so there’ll still be a market for a while.
A NAS is mostly geared for online media storage, whereas disks are for offline.
That’s just the government though, similar to how a lot of the systems in the US still run on COBOL (including the IRS).