Well, the truth is they couldn't. After Devil May Cry 3: Dante's Awakening was made, Capcom immediately started working on Devil May Cry 4. Back then, they had promised that this game would be available on Playstation 2. After a while, they noticed that this game, cannot be in Playstation 2, due to its limitations. Therefore they moved on Playstation 3 and shortly afterwards, to X-Box 360 and PC. However, they remembered their promise, that the next Devil May Cry would be available to Playstation 2, so they went back to Devil May Cry 3: Dante's Awakening to do some modifications. More pictures to unlock, Bloody Palace, a whole new difficulty, Vergil, Vergil's new clothes, and finally when they get to create more cut-scenes for Vergil, the disc did not have any more space. So they left it at that. They could not restart the whole project since they had their hands tied with the production of Devil May Cry 4, so that's how Special Edition was born. And that is why Vergil has only 2 cut-scenes.