I'm guessing that it may be Billy Joel's peeps that put this together since it was heard on his channel first. As far as the missing tracks that may be due to not getting the releases from those artists. Sometimes these benefits are put together so quickly they forget to get them signed and some artists do not want them heard if it's not their best work or their own band, etc., etc...
On a side note, I never knew there was a poor audience recording of this. If possible perhaps you could share it?