I'm not sure what Top Billing is, but they visited the Days of Our Lives set a few weeks ago and their interviews with the cast will be featured in next week's episode of their web show.
They posted a teaser video last night and although it doesn't show anything spoilerish, we do get to see some of the sets decorated for Christmas.
Someone mentioned earlier that South Africa is a few years behind the US. They probably wanted to interview people who are currently on their TV screens. And James may not have been in the studio that day or wasn't among the people that the show's publicists had sent to do those interviews.
If I am not mistaken, John & Marlena have been off screen for about a year now. So this is definitely not storyline related.
Aren't some of the Days cast going to South Africa in a few weeks ? Are the people they interviewed the same ones going in the trip ?