The hub document is delayed until this document is updated:
https://docs.google.com/document/d/117EDHqlOIYu7SIFg6ce8gOJs4PvE23nTewdWrMddUTU/edit
... in order to create a UBL 2.2 version of this UBL 2.1 table:
http://docs.oasis-open.org/ubl/os-UBL-2.1/UBL-2.1.html#d0e3616
I've called this out as a new ticket so that members realize it is a distinct action item contributing to the hub document.