The db br 101 has two formation options 7&11 car,theres a strange thing about this formation option and from what i found out about the 11 car normally had a cab car at the end.Could this mean a cab car was planned but there wasn't time to build one so it was scrapped.But the 11 car formation was kept anyway.
I dont think so DTG made it clear from the beginning they were going to do the cab car Because it would essentially be making a 2nd loco (according to DTG) And they were going to take the extra time to do the cab car