I suspect CBS believed Glor was too middle of the road and in order to attract viewers they needed someone who could narrate every story as opinion and high drama which seems to be the hallmark of all tv anchors.
They're looking for hysteria. ODonnell fits the bill but doesn't have the 'likeability' factor of other anchors.
That would be admitting they made a mistake.
You’re probably right.
However, Glor was quite likable and thoroughly professional.
I will not be watching O’Donnell. She is just another mistaken choice by CBS which has been struggling for many years, both in their morning program as well as their evening anchor chair.