Originally Posted by
rylan
The T&Cs for global certs state:
If you are re-accommodated on another carrier you will be seated in Main Cabin Class.
So while their 'rule' is to put you in Y on non-DL metal, obviously there are some wiggle room or overrides provided in some situations.
The T&Cs for global certs are backed up by the international contract of carriage language for misconnects/delays, Rule 80:
If the passenger does not request a refund and cancellation of
the ticket, Delta will transport the passenger to the destination on Delta’s next flight on which seats are available in the class of service originally purchased. At Delta’s sole discretion and if acceptable to the passenger, Delta may arrange for the passenger to travel on another carrier or via ground transportation.