From this article in Article from today's Los Angeles Times :

"The Met said the final decision was made after a series of discussions between Gelb and Abraham Foxman, National Director of the Anti-Defamation League, which represented the wishes of Leon Klinghoffer's daughters.

In a separate statement, the ADL said that Lisa and Ilsa Klinghoffer "have long held serious objections to the opera's biased portrayal of their father's death and its sympathetic view of his killers.""