One thing to keep in mind in terms of trying to discern a pattern for the interview invitations is that Sloan, like many other schools, hire seasonal readers and interviewers, and the same person often plays both roles, like all admissions officers.
At Sloan, some of these people live in Cambridge, while others live all over the world. So if a bunch of invitations are coming from, let's say, Los Angeles, it could be that the person in LA happened to finish evaluating his/her applications before the evaluator who's reading from Tokyo.