I love commentary tracks cuz they talk about the songs, the venue, the tour, etc and I hope they come back.
I don't buy the "it won't happen without Mike Portnoy" belief. They didn't do one for Live at Budokan, probably cuz they just did one for Live Scenes from New York. They didn't do one for SCORE even though you'd think that would have been a great time to talk about that show. Same for Chaos in Motion. I would say they probably didn't do them cuz they had documentaries but MP was there for these releases and we didn't get commentaries.
So, yeah, I know all the cool stuff MP did with DVD features, but there has to be reasons they aren't actively doing it right now but other than "we just did one", which they haven't, I don't see any good reasons to avoid commentaries. They cost almost nothing to make, 3 hours in the studio and adding another audio track to the final product (maybe subtitles also), so that can't be anything other than a minor consideration.
I thought for sure they'd do one for Live at Luna Park cuz it was Mike Mangini's first album/tour and it's been 10 years, but they didn't. Then I thought for sure they'd do one for Breaking the 4th Wall cuz it's MMs first 'real' album and tour and they have two albums/tours of music to talk about and it's been 12 years, but they didn't. So who knows. Someone needs to ask them at a meet and greet and report back.
It's a bummer that we'll probably never see any old stuff again, but in terms of current material I would think someone like Jordan Rudess would be all over it, but he also puts out a new iOS app every week so he's pretty busy, the guy is insane.