Look at how many leftover tracks they still had from FII, when I don't think they've had any unused songs since.
And I think it's a shame that this has happened. I mean, how many cool ideas for songs ended up on the cutting room floor just because they had 75 minutes of completed music? If they're on a roll, why not pursue some of those other ideas further and see how they develop? At the very least, they could be B-sides or saved as bonus tracks for compilations, and at most they might replace some of the lower quality songs that they originally were gonna have on the album. For that matter, if they feel that strongly about the all material, they could release a double album, or release 2 albums 6 months or a year apart.
I know it's a money thing, especially if they still camp out in the studio the same way they did for SFaM, SDoIT, 8v, SC and BCaSL, but I think there's some lost opportunities that could have been awesome. Had they simply written enough for FII to fill a single CD, neither Trial of Tears, Hollow Years and New Millennium would've never existed and Where Are You Now would have been on the album.
I remember talking to JP about doing more tracks than needed for an album in Dec 2011, and he seemed very agreeable to the idea, but I doubt this is the case considering they haven't done any extra tracks since then.