As of wallet 1.3 (pending release), update will be handling the 'get new data' functions of get. get will continue to work the same in the short term, but at some point in the future it should refuse to update the kvno when getting a keytab, so that get always works as if 'unchanging' flag was set. Then the only way to get a new keytab is to use update and it's more clear about what is happening in each operation.
As of wallet 1.3 (pending release), update will be handling the 'get new data' functions of get. get will continue to work the same in the short term, but at some point in the future it should refuse to update the kvno when getting a keytab, so that get always works as if 'unchanging' flag was set. Then the only way to get a new keytab is to use update and it's more clear about what is happening in each operation.