[chrisherald]

The BBC can't ditch all of the NC presenters who are left. I can't imagine the 5 "chief" presenters doing more than 4 or 5 days a week, so other presenters will be needed for weekends and potentially Fridays as well. 
Also, if Christian Fraser still stays on The Context at 9pm weeknights, then potentially an extra presenter will be needed from somewhere for a daytime shift.

Isn't that what the presenter-correspondant roles (yet to be revealed) are for? To help bridge the gaps in the schedule.

I thought those new roles were just a way to keep some people at cheaper rates, a technicality/process to evolve the jobs. Sometimes you have to "close" something to "open" something else, when it all amounts to parts of the same thing, with a new label on the tin at a different rate. Kenny Everett voice: We're not closing the news channel, we're closing two channels (!), to have one new channel, with two streams (and four wizards!), that sort of nonsense. It's a party trick, a slight of hand, a misdirection. But I'm guessing, someone else will know more.