This is already happening. Not too long ago my son asked me what that icon meant on the Save button. He’s 12. I dug out a 3.5 floppy and showed him, but I haven’t actually used one except as a boot disk in about 7 years or so.
Mangetout, Telemark meant we still dial a phone, but when was the last time you turned dials on a phone to call someone?
I’ve seen some games use an arrow pointing down to a CD for “Save” and an arrow pointing up from the CD for “Load”, which would still be current enough since a DVD isn’t visually different.