No One Understands Hogwarts Better Than I Do

I transmigrated and became Draco. With a family fortune this enormous, what else is there to say? I'm set for life! Obviously, I should cling to Harry for all I'm worth, then inherit my relatives' estates after Harry takes down the Dark Lord and his minions, and spend the rest of my days happily surrounded by Galleons. It's a perfect plan. What could possibly go wrong? After all, I'm a seasoned fan who's read the books, watched the movies, and played the games! Nobody knows Hogwarts better than I do! Wait! Why did Harry's wand choose me? And what do you mean Harry isn't among this year's new students?! If Harry isn't coming, what happens to my perfect plan?!