It sounded like he went to S Sudan in March and then for whatever reason (undoubtedly to do with the geopolitical situation of the time), it was decided not to publicise the trip.
The photographer posted some pics which were only found out about by Torrilla (ie: not actually officially released by anyone, including UNICEF). Their prompt disappearance seemed to indicate that UNICEF didn't want the trip to be publicised.
I thought that it was a bit misleading for some to suggest that the trip was a way for Tom to publicise his films (since the story came out in September).
I do think though, that it is now too far along the line for anything generated from the trip to be useful to UNICEF.
Having said that, it is amusing to sit on the sidelines and watch people suddenly concerned about the plight of the South Sudanese (though wonderful if it is actually enlightening them about this very poor country).