I did, and apparently as of today, fare code PN replaces ZE (for M and B-ups). There is also a new fare code JN, which replaces FN.
Any one else get that same response?
I believe "JN" is the new COS for "FE"' Y-Ups. All of my reservations which said FE previously are now listed as JN (Both First and International Business). They weren't reward tickets, which is what I believe FN was.