I don't know if they changed, but were the groups really uneven size-wise? The only way the places going out to those numbers makes sense to me is if they did it as a percentage of the number of boys competing in each group (so a very small group of 7-8s, a small group of 11+s, and a huge group of 9-10s).
At our meets last year, if the boys were grouped together, the age ranges were always the same, but at some big meets they broke them out into smaller groups. So, to give an example, the youngest group was always either 6-7 YO or separate 6 and 7 awards at L4. I think for L5, it's 7-9 for the youngest group but they have the option of breaking it up so the younger guys have a shot at a medal. But for L6, having a separate group for 7-8 seems like it would be pretty darn small at most meets. I suppose it would have been more complicated, but for your meet, it would seem like breaking up the 9s and 10s would have made more sense.