He definitely has enough material to fill a double album, he could divide the two discs with two different period.I don't see this Lost Tapes being like the last. It was promoted as "no hype, no BS". I think it will stay true to the "no BS", but this definitely has hype. Like 16 years worth of hype. I think an advertisement was inside the booklet for The Bravehearts album.
It is unlikely, but I think a Nas Lost Tapes could make for a classic double album.
Something like :
Disc 1 : 2005-2008 (HHID and Untitled sessions)
Disc 2 : 2010-2018 (LIG sessions and song recorded from the album he was working on before Nasir)