The Official Lucas Canon has changed however. It is no longer even static like it was after 1983.
The original threatrical versions and the 1997 versions that became the new canon versions are both now taken out of canonicity and the 2004 versions replace them.
The radio dramas and novelizations have been thrown out as canon because they contradict the prequels.
The funny things about the prequels is Lucas paid zero attention to continuity with the older films therefore he contradicted his earlier self in the making of them.