The Russian soprano, one of the Met’s biggest box-office draws, “will not sing Violetta in New York during the 2010-2011 season.” The much anticipated new staging “was to be a version of the Willy Decker production the soprano did at Salzburg in 2005,” presumably imported by the Met for her sake. Netrebko said she has “a concern that she might not be as effective in the staging as she was in the well-known DVD release.”