It's going to happen one day. When Em is done rapping or dead, a lot of his songs sitting around locked away will see the light of day. There are some songs that us stans have heard a million times on there as unreleased, because even though it has leaked, it hasn't been officially released. There will also be a lot of stuff we have never even heard.
Most artists have enough stuff to release one disk of good stuff, then another couple disks of mediocre demos and stuff that you can see why it wasn't released.
With Em, he records so much, we might get a lot of quality songs.
This thread was inspired by the boom box sounded Our house that I have been listening to for the past 13 years. A high quality version of that will probably be on the box set.