Glad you made it. The cross-fleeted flights (not the same as code-shared) primarily go by the rules of the marketed carrier. Even after June 1, even though PDX-NRT is a DL equipment, most rules, including nonrev listing, priority, etc. will be as NW. Your NW pass would still work on this DL plane. It's also true that being "rolled over" to a different routing, even departure city, can be done, but could depend upon the particular agent at the counter. The 1-800 number above is a res number for listing and most agents may not be able to answer your type of question; they'd have to call their support. The travel desk or the airport agent would be more knowledgable. Chew some betel nut for me!