As for my own opinion, here is what I wrote to my brother:
While media coverage of things like this tend to oversimplify for the sake of sensationalism, this one does make a good point that composers write a variety of pieces, each of which may or may not contain elements of the composer's sexuality. I think some of Tchaikovsky's pieces have a tumultuous quality because of his struggles with his sexuality (he married a female student who ended up committing suicide). I think Benjamin Britten gravitated towards operas about the other, because of his "love that dare not speak its name." But then, Britten also wrote the War Requiem to portray his pacifist beliefs, nothing to do with homosexuality.
Terry Teachout recently addressed the question of his sexuality, pointing out that it only mattered to those who were interested in him romantically. In other words, the CJ Craig line. I agree with this, when limited to the form of interactions with the person. But when looking at artistic endevours by someone, biographical information can be illuminating. A former professor of mine determined that Elgar had deliberately quote Wagner's Prize Song in his Second Symphony as a love letter to Mrs. Stuart-Wortley, proved by more traditional love letters he had written to her at the same time. (Gimbel, Allen. "Elgar's Prize Song: Quotation and Allusion in the Second Symphony." 19th-Century Music 12 (Spring 1989): 231-40.) Being aware of the extramusical influences of this quotation provides many interpretation possibilites for the performers. Likewise it could be helpful to know that Schubert was gay, in interpreting some of his songs.