Here's a quick list of the (presumed) living voice actors from the first 20 Disney Animated Classics. It includes both credited and uncredited performers. Quite a few of them only ever had a small speaking role in a single film, and so I doubt they would get an obituary meaning a few of these could already be dead. The most recent film to have no surviving cast is The Lady and The Tramp (1955). The oldest surviving Disney Princess is Mary Costa, who voiced Princess Aurora in Sleeping Beauty and is aged 87.
Snow White
Pinocchio: Patricia Page
Fantasia: Corey Burton, Hugh Douglas, Tim Matheson
Dumbo: Harold Manley, Tony Neil, Billy Sheets
Bambi: Stan Alexander, Bobette Audrey, Peter Behn, Janet Chapman, Jeanne Christy, Dolyn Bramston Cook, Donnie Dunagan, Ann Gillis, Babs Nelson, Sandra Lee Richards, Francesca Santoro, Bobby Stewart
Saludos Amigos
The Three Caballeros: Dora Luz
Make Mine Music
Fun and Fancy Free
Melody Time
The Adventures of Ichabod & Mr Toad: Edmond Stevens
Cinderella: William Phipps, Earl Keen, John Woodbury, Lucille Williams, Clint McCauley, June Sullivan, Helen Seibert
Alice in Wonderland: Kathryn Beaumont, Bob Hamlin
Peter Pan: Kathryn Beaumont, Paul Collins, Tony Butala, Carol Coombs, Connie Hilton, Margaret Kerry, Karen Kester, Johnny McGovern, Norma Jean Nilsson, Jeffrey Silver, Stuffy Singer, Anne Whitfield
Lady and the Tramp
Sleeping Beauty: Mary Costa
101 Dalmatians: Cate Bauer, David Frankham, Lisa Davis, Mickey Maga, Barbara Beaird, Mimi Gibson, Sandra Abbott, Jeanne Bruns
The Sword in the Stone: Richard Reitherman, Robert Reitherman, Fred Darian
The Jungle Book: Bruce Reitherman, Clint Howard, Chad Stuart, Lord Tim Hudson, Darleen Carr, Leo DeLyon, Pete Henderson
The Aristocats: Lord Tim Hudson, Dean Clark, Liz English, Monica Evans, Carole Shelley, Roddy Maude-Roxby, Ruth Buzzi, Peter Renaday