It's been a long journey, and I'm very fortunate to be in this situation. I've be admitted to 4 schools and have decided to go to HBS. However, I have been receiving many phone calls and emails from students from the other three schools. What is the more appropriate/polite thing to do? Should I just tell them that I have decided to go somewhere else or do I politely let them know if I have any questions that I'll reach out to them?
I think you should tell them you've decided to go somewhere else. I'm sure you are among others on their list of people to keep track of and call, and it would be a courtesy to give them the heads up that you have plans to go elsewhere.