Willie's diary is an interesting insight into the band's thought process. For one, they obviously have their hands tied by the production elements. They feel that inserting any song is like replacing a wall in a house - there are all kinds of structural issues to resolve. It's not as simple to them as plug 'n play, which is too bad in many ways.
I also find the contradiction in logic somewhat funny when the band felt they could drop the wildly popular Ultraviolet because it was "on the DVD" yet there are numerous other songs they've marched out for several DVDs.
Although, I must admit, I'm glad ensuring songs make it on a DVD is a concern to them. I hate when a song was a highlight of a show, yet never makes it on a DVD. TTTYAATW is a classic for me. I realize why it never made the Zoo TV DVD, but that was a real shame to me. It was such a great connecting part of that show. Here's hoping it returns on 360, as per Willie's comments.