I also received a invite for an interview with MIT.
I am also an international student but completed my undergrad in the US... but I find it hard to believe that just the international students are being interviewed.
Then again, I dont presume that all students would be interviewed.
From the MIT website:
Is an interview required?While an interview is not required, the admissions committee may want to speak with you to gather additional information following the initial review of your application. Please note that interviews are by invitation only and may be conducted in person or by video, depending on availability of the applicant and interviewer(s). Arrangements and detailed information will be provided if an interview request is extended.
So there you go. Dont worry folks, fingers crossed!