More details are out in a Globe & Mail story: Apparently Bell/CTV offered her a chance to wind down and say goodbye, but she chose not to do so. She also had two years left on her contract. The story goes on to mention that Michael Melling, the VP News, was a penny pincher, and that LaFlamme pushed back on his cheapness on two occasions. One was on the coverage in Ukraine (she wanted them to reserve hotel rooms in Poland in case the field crew needed to evacuate quickly), and the second was coverage of the Queen's Jubilee, where Melling didn't want any one doing coverage in London, all from Toronto.
The story also mentions Melling was questioning who allowed LaFlamme to let her hair go naturally grey. Which, to be honest, was gutsy on her part (and I respect her for doing it). So, there is a mix of ageism and sexism in this story, as most of us suspected.
So, my take: Melling is only the VP of News. To make a move like this would require the president's approval, and it probably came down from the top. Melling might have had the idea first, but would need executive sign off, maybe even from the head of CTV/Bell Media. It is a HUGE move to axe your main anchor in this fashion. Then they compounded it by naming Omar, and forcing local affiliates to do a talk back with him on that day. PLUS!!! He was forced to tweet about getting the new job. They basically put the poor bastard into a no-win situation.