Man, SEED is FAR from the only Gundam show to have recycled its battle scene animations (also, I thought SEED Destiny was the one the internet picks on for it REALLY being noticeable).
I can't say this is that big a surprise. SEED started what is considered The Second Gundam Boom and is old enough now for the teenagers who watched it in high school to be adults with disposable incomes. It only makes sense you'd offer them something they'd have nostalgia for in a prettier package.