By Carmen FormanStaff writercforman@oklahoman.comThe University of Oklahoma and Oklahoma State University are reviewing proposed federal guidance that would require international students to take classes in-person this fall in order to remain in the country.Federal immigration officials announced Monday proposed changes to the Student and Exchange Visitor Program, but by Wednesday Harvard and the Massachusetts Institute of Technology, which plan to have classes entirely or mostly online this fall, filed a lawsuit seeking to block the changes from taking effect.The proposed changes, from U.S.