Is diastereomeric excess sometimes interchanged with enantiomeric excess in publications?

There is no endo/exo-isomerism with symmetric fumarates. There is always one substituent being pseudo-axial and one being pseudo-equatorial.More

They use the diastereomeric excess here, because they already use enantiomerically pure starting material (the fumarate) to produce a single diastereomer. This is known as chiral auxilliary.More

So no, de and ee are not interchangeable.More