Did you even read your link:
“Unlike most other airlines that failed during this time period, the Shuttle was still a valuable asset given its business-oriented customer base and access to slot-controlled airports in New York and Washington.
Citibank put the airline up for sale, and after some lengthy negotiations with Northwest and American, settled on a deal with USAir Group.
CITIBANK GOT THEIR $$$!
You don’t seem to understand what ‘default’ means. Yes, they sole the assets, but THEY DIDN’T GET BACK WHAT WAS OWED! They were stiffed by Trump. If it was worth more than was owed, it would still be called Trump Airlines.