I think they really wanted Our New World to become a well know radio hit. They postet their (imho not very good) version with Lzzy like a THOUSAND times on their FB wall, saying "check this out". Most of the people replied to that post with exactly my thoughts. Thank you! We have seen it, stop throwing it into our faces, it's not at all a big effort to shorten a song and let a female singer sing on it.
When I think of (very long existing) Prog bands that have NEVER sold out, the only ones I can think of are Crimso, VdGG and maybe Rush (although their style has moved away from their typical Progrock sound of 75-81). I would dare to say, Dream Theater are amongst them. Sure, they made albums like Falling Into Infinity (BTW I AGREE!!! Very good sounding album, for me, the BEST Snaredrum sound any DT or Portnoy album ever had. That pickup on Trial Of Tears, wow!). Also TA had shorter songs. But who in earth would call releasing a 130min Prog Metal concept album a sellout?