I recently opened opened up an over three-year-old Ableton Live project, and remastered and otherwise redid the contents. It was interesting, and I was very pleased I could open up old Ableton Live projects without any issues.
Which leads to the topic of preservation. It’s good to save projects for later use, remastering and so on. Today it’s even easy, if you want to read about problems and issues, check out how much hard work it’s to go through the archives of Frank Zappa, tapes belonging to old tape recorders no longer in production, analog tapes slowly getting worse, and so on.
Depending on your work flow you might have a DAW project with a combination of MIDI and audio tracks. Most modern DAWs nowadays have a feature of self-contained projects, so always use this. You could then save the project on a hard disk, DVD, and so on, and not worry about broken content links.
In my work flow it’s common I do a lot of initial work in Logic, and I just export the final audio material as 24-bit AIFF files that I then assemble together in Ableton Live. I still save the Logic projects so I could go back and redo or re-edit various MIDI sections. I might even start exporting the pure MIDI tracks as those are good to have around.
One worry is that if you just keep the DAW projects around without any audio dumps, the plugins such as the software synths might not work years in future — we saw already issues with the MacOSX to Intel transition where various plugins, especially VST ones, have not yet been ported over. Or, the public domain synth is no longer actively developed.
You could also use freeze tracks to save the information. Also, both Logic and Live has a feature of dragging freeze tracks into audio tracks, and this way they are saved as pure audio tracks. Anyway, just always preserve your audio projects, if nothing else your grandchildren will have great fun discovering ancient material while they dig through the attic.