Seems a bit of balance was being secured by raising 15 women in 3 years and additional 3 over the next couple of years, for a total of 18 new Aes Sedai raised between 978-982 (for these 18 the average training time was an even shorter 13 years). These 18 women were mostly quite strong for Aes Sedai too, with only 3 being below the level 19 threshold for Traveling.
Given that I believe strength and length of time in training appear to have an inverse relationship in the books, if the 18 women were mostly quite strong, isn't it likely that regardless of the Vileness, they would have been raised then anyway?
Thus is there potential that rather than it being an active reaction to the Aes Sedai deaths, it is more the Pattern asserting itself, having stronger channelers emerging at a time when other channelers would be dying?
First I'd say that the material supports stronger women advancing somewhat faster, but the timing of their advancement also seems to play a role. For instance Cadsuane advanced quickly, but Elaida, Moiraine and Siuan advanced faster than she did. This was despite their own behavioral issues and the fact that at least Siuan and Moiraine were still several years away from achieving their full strength potential.
The pattern might well be spitting out stronger channelers, but the Aes Sedai are a very political group who would see the dip in numbers as a potential weakening of their own power and IMO would take steps to ensure they maintained.
In addition I would say that stronger channelers also advance somewhat faster because they typically hit the requisite strength for each level somewhat quicker. Hitting level 45 is a lot less as a % of Cadsuane or Elaida's strength than it is for someone like Cabriana at level 34 and ended up taking 19 years in training. But she spent a significant amount of time as a Novice (12 years) and only an average time as an Accepted (7 years). I'm theorizing that part of this was gaining enough strength to move forward from Novice to Accepted took her a long time as she would have needed to be at a much higher % of her overall strength to achieve the ring and then the Shawl than women like Moiraine or Romanda or Sheriam.
