There are still some regular SACDs that are being produced, though the format has evolved to almost exclusively target the audiophile market. Most SACDs that I hear about these days are classical remasterings or jazz recordings. I wouldn't quite say that it is extinct just yet.
Regarding floppy discs, Konami's MIDI Power Pro albums include floppy discs with MIDI arrangements on them, and I've seen some Falcom MIDI arrangements on floppies as well:
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