Did you indicate on your application that you would complete the program by May 2017? If so, that's the applicant they believed they were interviewing. You will most likely need to finish.
Schools run statistics on how many students matriculate with what background. Lots of schools like to boast how their incoming students are coming in with Masters and PhDs and that it is VERY competitive to get in. That's the nature of it. Chances are, they expect you to finish.
But call them and ask. If they say, "Hey pal, drop your classes, forget the degree, chill until August!" Well then that's great! You have to call and find out.
Best of luck!