I am responding as a member of the AOU-CLC.
First, we made a mistake on the English names of the Scoters. On our proposal they were listed as
M. nigra Common Scoter
M. americana Black Scoter
Somehow these got convoluted during the manuscript preparation and switched to nigra = Black, and americana = American.
We are going to publish errata in the next Auk that will have nigra = Common Scoter, and americana = Black Scoter.
I originally posted the query here from the AOU-CLC regarding the wren names. The CLC does give some weight to what the public thinks and how they may react, although the conversation on this board did go a little off-topic. As I recall, there were a number of responses favoring that hiemalis stay as Winter Wren. If we went into the murky waters of group names (hyphen hysteria), we would then have to also have the Old World troglodytes have the group name "Winter-Wren" as well, which would not likely be very stable globally. English names service a very diverse audience (not just records committees) and a majority of the Committee felt that Pacific/Winter was best. If the California BRC has to deal with a few confused submissions, the world will not stop.
As far as the Polioptilidae, they come are placed after Cyphonrinus phaeocephalus. The Calcariidae are placed after Peucedramus taeniatus. The supplement spells out the sequence changes in detail. The AOU website will be updated shortly with the changes
I'll keep monitoring this thread for comments, opinions, and any problems.