How are DLPM and TLF "part of I&W?" They aren't. They were written during the lead-up to I&W, but so was ACOS, for example. Those songs are all on equal footing in terms of being from that era.
I mean they're part of that album in some way, as bonus tracks at least.. ACoS and Eve don't count as that, because they were released years after, in a EP format one, and in a single the other.. They're equal about being from the I&W era, yes, but they're not in terms of what really matters here: DT celebrating 25 years of I&W, the album, not the "era"..
No, you are misstating Portnoy. He never said "we don't play any KM song." He said, basically, Space Dye Vest is a "Kevin Moore song, not really a Dream Theater song" because Kevin wrote the entire thing himself and brought it in, and it didn't really match the vibe of what they were doing as a band. He has never said anything about not playing any songs that KM wrote or contributed to. They have played a bunch of others through the years. I think it is likely just what you said at the end of your post in terms of it just being a song they don't like very much, and there are plenty of others to choose from.
Either way, is pretty much the same, because I was talking only about the songs that KM composed by his own.. Obviously not about the ones that he helped to make.. And even so, yeah, I know they played WFS several times without KM in the band, but Eve and Space Dye Vest demonstrate well that it was Portnoy's decision..
What I tried to say is, if they don't like it, why play it lots of times before the lineup change? it's not like Jordan joined and then they suddenly don't like the song. They already had a couple full albums and a few demos/extra songs to play, but chose to play Eve instead. It might be due to Portnoy's excessive control over the sets and stuff, but I still it doesn't make sense
I don't find it something that hard to guess or understand.. The track was created by KM, and it's obvious that he liked it, but maybe he was the only to like it, or at least the only guy who claimed to play it live.. Once he leave, they hadn't any reason to play it, except the fact that it was, after all, a DT piece that probably have fans who like it..