Originally Posted by Sora2311:
“It would make sense seeing as how the first was 30 minutes and the second has been announced for ages”
Children in Need never announce the exact time something is going to be on as they usually never stick to schedule.
So the DW sketch will (probably) be on within that half hour it won't last half an hour.
None of the sketches on CiN would ever last that long as they could end up losing a large chunk of their audience who are not interested in that particular segment.
Plus if a 2nd 5ish Doctors had been filmed there would have been something known about it by now.