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?