As for the actual new material -
well, it does seem a bit odd to me to include these unfinished ideas. I mean, every musician has tapes of noodles like these - unfinished things that never got turned into songs, or that got recycled into songs later.
As John explains in interviews, the synths and equipment of the day had no memories, so often you'd record stuff onto tape just as a record of the sound, if you thought you might want to use it in future.
Similarly, we get rejected mixes of Glimmer and Mr No - they're clearly not as good as the mixes he decided to use (in those days, every mix was a live real-time performance event!)
Don't get me wrong, most of them are just the sounds you can make with an ARP Odyssey and a nasty phaser/flanger/reverb slapped onto tape, and they sound great
And I suppose galleries sometimes even show artists' pencil sketches and studies for later paintings, so here we have some analogous audio stuff for John's work of 1979/80.
On the other hand, there's only so many of these out-takes and bits of fluff you can include without kinda diluting the brilliance of the original finished album, even if you do give it its own CD.