[...]might have been anxious to have Interplay fail[...]
I'd say Interplay failed years before this deal. And it's Bethesda's money that has allowed them to keep doing whatever it is they're doing (mainly just baiting investors perhaps).
I wish Caen would stop propping up Interplay's unholy corpse and let it rest already. The only thing I would fault Bethesda with is having given them enough money to pay off their debts, since otherwise Interplay and Caen would be long gone by now.