Have you tried an SWU upgrade since UDU came into play? When I did, UA.com, by default, applied the SWU to waitlisted International segments and creating a "pending" UDU upgrade (near as I can tell anyway) for the domestic.

I wish I'd printed out the relevant screens as I purchased and upgraded the tickets; could be that my memory is faulty, but I'm pretty sure I chose the defaults for the SWU, which, in the past, would have applied to all segments... but this time, it didn't.

Just curious what others are seeing, since it's going to be some time before I get to play with SWUs again.