Official are the ones that had an Unsourced template last monday when Ales updated things or let's say when he made an Inventory of all profiles that had the Unsourced template, so all those profiles from that Inventory are the Official ones.
Unofficial are the ones that didn't have the Unsourced template yet when Ales made the Inventory, or perhaps never had the Unsourced template, but that perhaps are Unsourced as well, at first it was decided they would not count, but now they do..so... if for example you are sourcing parents that both had the Unsourced template and discover the children or other familymembers all are Unsourced as well, but there was just no Unsourced template added to those, you can now also source them and they will count ...and those are the ones you will see in the Unofficial list if I'm correct .