The issue is crystal clear.
Groups have a clear right to define who they are and what they stand for.
Orthodox Catholic or Jewish students will not let women be priests or rabbis. The institution has actually no business in trying to tell these groups and others what to believe. Many other groups define themselves as favoring or opposed to a wide range of things such as abortion or homosexuality. The groups define themselves. If the university allows student groups to exist and use university property to hold meetings.