So I've been doing another run of the historic campaign and noticed something. Winning the hunt for the malevolence as the CIS with the subjugator intact.

The opening cut scene in for the Rimward campaign was changed. In 1.4 Grevious would show up with the malevolence and defeat Anakin and his fleet in what was supposed to be a loss for Grievous.

In 1.5 however Grievous would only appear in a munificent frigate, and you would lose. I don't know if you can beat it, personally the best I ever did was destroy a single venator before I lost all of my ships because of the AT-TEs on the asteroids.

Was it changed because the cut scene broke?

Because thats what happened to me when I last played it. I would win and the twilight would show up, but because Grievous was right next to it, he would just unload all over the tiny ship, and shortly after my computer would crash.