Their letter, which one of the signatories made public, is here.  The letter itself is a symptom of the "group think" pathology afflicting American higher education, but more to the point, if the faculty candidate, an associate professor at the University of Toronto, was denied the job because of this, then UCLA engaged in unconstitutional viewpoint discrimination, which is exactly the worry about these "diversity" statements.  The irony, of course, is that the U.S. super-legislature is about to declare "diversity" an unconstitutional consideration in college admissions.  Whether the opinion has implications for employment remains to be seen, but it's hard to see how universities can require statements about a constitutionally impermissible consideration.