I see the similarities in the two; they could be the same, although how they completely re-arranged the class in the short distance travelled (the car is the same in both pictures, so they are pretty close to the same location) is problematic.
And the fact that none of the other kids match is also an issue. Several people have papers in their hands as well, so that isn’t definitive.
It seems odd that they would take the kid from the front and the kid from the back, and then move them to the middle, when all the kids are linked together.
That is why I suggest that it is two different classes. Although if all I saw was the one boy you mentioned in the two pictures, I would totally agree with you.
There would have been dozens of these groups, to get all the kids from the school to the firehouse.
Another thing that would suggest the same group rather than two — if the reporter just got out the camera for a few quick shots, it would make sense to have two pictures of the same group.
They are not the same boys IMHO.
Look carefully at the images on the shirts. One image stops at the chest level and the other goes down almost to the waist.