The CBC always includes the voice of the Oppossition - ALWAYS. When the Opposition was the NDP, Mulcair was all over; when It's the Liberals, it was their leader you heard all the time.
It's annoying as hell right now, but it's not anything new they're doing.
Having said that, I do feel like PP is being showcased a bit. I suspect that the CBC has some confidence that the more Canadians hear of him, the less we like him. #mapleMAGA eh.