这个user_registered 字段不在中wp_usermeta, 但是wp_user. 您应该使用wp_update_user:

add_action( \'show_user_profile\', \'extra_user_profile_fields\' );
add_action( \'edit_user_profile\', \'extra_user_profile_fields\' );

function extra_user_profile_fields( $user ) { ?>
<h3><?php _e("Información AbIbBEV", "blank"); ?></h3>

<table class="form-table">
<tr>
<th><label for="user_registered"><?php _e("Fecha de ingreso Empleado"); ?></label></th>
<td>
<input type="text" name="user_registered" id="user_registered" value="<?php echo esc_attr( get_the_author_meta( \'user_registered\', $user->ID ) ); ?>" class="regular-text" /><br />
<span class="description"><?php _e("Fecha de ingreso del empleado."); ?></span>
</td>
</tr>
</table>
<?php }
add_action( \'personal_options_update\', \'save_extra_user_profile_fields\' );
add_action( \'edit_user_profile_update\', \'save_extra_user_profile_fields\' );
function save_extra_user_profile_fields( $user_id ) {
    if ( !current_user_can( \'edit_user\', $user_id ) ) {
        return false;
    }

    wp_update_user(
        [
            \'ID\'              => $user_id,
            \'user_registered\' => $user->user_registered,
        ]
    );
}