I don't think they'll be played either, but not exactly for that reason. If nobody in the band actively wants to play a song, it won't get played.
Absolutely true. But I can't imagine that in most cases the band is gonna want to perform some of those songs with MP penned lyrics partially because of the lyrics.
I don't give a rip if a song is "too personal" to a member who is no longer in the band. If it is a good song, play the damn thing (I don't know if any of those Scotty listed as such qualifies, I am more speaking on principle).
I don't think it would be so much a matter of them doing it out of respect for MP as much as they just don't feel comfortable performing the song because of the lyrics which the rest of the guys don't relate to or don't agree with.
I doubt the band would have a problem playing a "Derek" song, and I have a hard time calling Lines in the Sand a "Derek" song. Okay, he wrote that bad ass intro, but it's still very much a Dream Theater song.
Well considering how DS and MP are now in a band together, and they just performed JLMB and LitS with their band, I can easily see them steering clear of those songs for that reason alone (not wanting to be compared to SoA's performance of the song). Not hard to do given the huge catalog of other songs they have to pick from.
It remains to be seen how many touring cycles the band has left (maybe a handful?), so I am sure the list of songs that will never get played again is longer than any of us realize, especially given how static the set lists have been the last few years. Heck, four of the 10 new songs from last year have yet to get played despite a year of touring on the album now, and the first three Mangini albums have all been poorly represented live other than the touring cycles on those albums (Breaking All Illusions being the exception).
The static setlists are definitely part of the problem - had they kept the rotating setlists or at least alternating setlists, they could include many more songs within a tour cycle. And while I know it's controversial, I think it would be nice to include a medley, highlighting the best parts of various songs that they otherwise will probably never play again, such as the instrumental sections of NE and TMoLS, the outro guitar solos to TBoT and ANB, etc. I mean, I know it will never happen since JP hates medleys, but it would be one way to satisfy playing some of these songs.