It makes sense. A military is only as good as its logistics, and the US’ forward bases are the tips of very long spears, dependant on a lot of logistics. So you need to have the means to have a continuous pipeline of supplies to each outpost. In peacetime, you keep that open by supplying the troops with burgers, tacos, XBox games or whatever; if the shit does hit the fan, all that capacity can be diverted from tortillas and patties to ammunition, drones, amphibious landing craft or whatever, at short notice.
They should improve the quality of food in sewers so that those who bought sex and thus reincarnated as rats and cockroaches can get a second chance in their next lives
If you’re paranoid, you can convert the FLACs to WAV on an isolated computer (or VM), copy them and recompress them to FLAC or other formats. If there is a vulnerability in FLAC, it won’t persist through transcoding.
On Windows, there is a Secure Audio Path API to prevent interception of the audio signal. Not sure if macOS has something similar, though it can prevent screenshotting of DRMed video. On Linux, any such protection is probably impossible unless Spotify requires a kernel module.
Note that the audio quality on Spotify is not very high (256kbps .ogg, I think), so anything thus recorded is going to sound lossy, especially after you recompress it a second time.