hahahah you fell for it! hook line and sinker.
why is it a joke?
I dont follow US schedule but I do know for a fact that CO,UA,AA,DL ALL at times have their widebodies flying on Domestic routings in order to repostion the aircraft
So with say CO its very possible to get a 777 with the new BF lie flat bed seats between IAH & EWR. DL flys a 777 between ATL & LAX etc etc
Thusly w/o knowing USs sched I would think possible if they use a certain type of plane out of more then 1 of its hubs that its very possible to get a wide body on the routing. If they dont fly Intl from LAX or PHX then they probably wont have them. But its very far from being a Joke