Clearly there are a vast array of Healing weaves and various Talents in the area... So it is not a shock that at least some was lost. But it defies rational thinking that every scrap of Healng knowledge with the exception of one Weave was lost. Traveling is essentially one weave that requires a Talent and/or a level of strength that makes it reasonable to assume that it could have died out quickly during a time of upheaval. Healing on the other hand seems to have been an entire field of study during the AoL ... Certainly areas that require rare Talent or great Strength or specialized equipment would be lost, but to have the entirety of a Profession disappear seems more I plausible to me than the loss of Traveling. Especially when it is a field of study that would be critical in a cataclysmic event. Seems funny that the Printing Press survived the Breaking, but something as critical as the healthcare system devolved to what we would essentially think of as sticking leaches on someone to draw out disease.

We all understand the hows and whys of Nynaeve's discovery and that not all Sisters with the "standard" Talent will excell at the new weaves, but there have also been dozens of women who show great promise with the Weaves ... So this Talent is obviously not as rare as something like Dreaming or Fortelling, and clearly these new Weaves don't require massive Strength as many women are already using it. Not to mention during the Breaking with little if any education women likely were put in positions on an almost daily basis where the standard Weave would not be useful, or would kill someone ect... As the saying goes necessity is the mother of invention ... You'd think some woman along the way would have discovered alternative methods.