Nice and neat, but a half-baked solution. It doesn’t support sortable columns and seems to ignore any attempt to use the old code to make them sortable.
The show_admin_column arg to register_taxonomy appears to be a quick replacement for the filters: manage_{$post_type}_posts_columns & action: manage_{post_type_name}_posts_custom_column
The new taxonomy column in the post-type list could be set as sortable by using the filter: manage_edit-{$post_type_name}_sortable_columns
This is ignored now if using the new argument, probably due to program flow. An oversight or a bug?