I requested a Brandeis alumni interview a few weeks ago. I called to check on the status of finding someone, and got an e-mail saying that this year they have received an unusually high number of requests for interviews, and it was pretty unlikely that I may not receive one. They assured me that it wouldn’t hurt my application if I didn’t have one, and gave me the option of emailing back a self summary to attach to my application. Not sure if I should do this- and if I do, what does this entail?
I think you should do one as long as you have someone review the summary before you send it to the school. Still, unless you are REALLY sure that it could add something to your application, don’t send anything 
Wish you the best!
Emily