Originally Posted by
Adam1222
The OP needs to clarify if by "PE", he means he paid extra for Delta's economy comfort (or whatever the new name is) seating, vs a ticket to fly PE. The former is considered paying for a better seat, not a class of service.
But this is all a hypothetical based on the fact the OPs friend said a downgrade could happen. Lots of other things could happen too....
She paid more for their version of premium economy.