What you study in undergrad should help prepare you for your first job. After a few years of work you may very well learn that you don't need an MBA to continue on the path you want to go. Many business school students are pursuing a general business education to help switch careers, while others are continuing on a track like investment banking.
I completed my MBA almost a decade ago, and had done a double major in computer science and general business for undergrad. Most MBA students did not study business as an undergrad. One of the greatest values of going to business school is learning from your classmates, and having diverse backgrounds adds to this.
If you are confident in the need for an MBA in the future, a well rounded undergrad business degree may reduce some of the foundational classes you take in graduate school, and allow you to pursue more advanced studies. Some business schools require foundational classes like Accounting for all students, but even so your familiarity with the subjects can allow you to focus efforts on classes that are completely new. From my experience business school classes are much more in depth than undergraduate, so you may still want to take the same classes as you took in undergrad. One of the biggest differences is the case driven nature of MBA classes, and input from your classmates based on their real-world work experience.
My advice is to not over-prepare for attending business school, and instead focus on preparing yourself to succeed at your first job. If that is a business role, take classes that will help you get a head start there. You will learn a lot more on the job than in class. If you aren't interested in a business role immediately, then feel free to pursue another major, whether that is art history or computer science - as long as it helps you succeed in your first job. Business schools want to help students accelerate their careers, and so are looking for candidates that are already succeeding in their previous roles.