That's a serious sentence of music criticism, if I've ever seen one.
The above statement, I must assume, comes from a place of love. We don't owe Britten (or Cage, or Mahler, or ...) a year of musical celebration, because such a year would exist only to remove the music from the performances and replace it (and any associated connections or missed-connections between the performances and audiences) with a vague sense of "appreciation" for the supposed historical relevance implied by the mere existence of a centennial event.
And even if the centennial or anniversary celebration is a success, in the sense that it invites the unearthing of lesser-known or more difficult to muster works from a composer's catalogue, the success exists at the expense of subjecting audiences (and potential audiences) to simplistic marketing. Perhaps an anniversary is a good time to recall the historical significance of a composer's work, or to tie it to external historical events — I just don't see how an acknowledgement of age is supposed to make people connect to music.The kind of people who might be excited about a Britten anniversary are the kind of people who are excited to see any performance of Britten (such as myself).
Peter Grimes isn't good because it's old, or because it was written by a composer who was born in 1913. I'm not the best qualified to tell anyone why it's good, in fact. But I'd hope that no one attends a centennial performance in the coming year thinking "wow, 100 years — I'm going to like this!"