The final Intro has the best CGI scenes from the old one, plus new ones that are even better. The whole Nomad destroying Earth thing was pointless. It gave away the enemy too soon, and it served no purpose. It also undermined impact of the Alliance’s ultimate defeat in the hands of the coalition, which lasted just a few moments. By cutting it they made the dramatic scene of the sleeper ships breaking trough the coalition blockade the climax of the movie.
I understand any opinion on this matter is highly subjective, but, to me, it boils down to this:
“We will never forget…”
… the ultimate defeat of our alliance, and the sacrifice made by millions so we could be here, today!
or
… that evil aliens are out to get us!
And LOAF, I think you a right, and they probably also needed some backstory explaining the origin of the colonies anyway.