RJ has already said that the Pattern can create t'a'veren or give t'a'veren abilities to people in very specific situations as needed.

"For kcf, again, we have never met anyone who has the Talent of emulating the effects of a ta’veren over a small area...The Wheel creates ta’veren at need, making someone who is already alive one. You aren’t born ta’veren. Can you imagine being around a ta’veren who is teething? It would be possible for a Darkfriend or Forsaken to be made ta’veren, but it seems unlikely. Ta’veren are part of the Wheel’s self-correcting mechanism. When the Pattern seems to be drifting too quickly, and especially if it is in the wrong direction, one or more ta’veren are created. I can’t really see how making a Darkfriend or Forsaken ta’veren would help with correcting the drift of the Pattern. Ta’veren can oppose one another, when their conflict is what the Wheel “sees” as the necessary corrective. And, no, ta’veren is not Old Tongue for Deus ex machina. It came out of musings on luck, charismatic leaders, and the theory of the indispensable man..."

I also think it's funny how RJ notes that ta'veren doesn't mean "deus ex machina", yet it serves the same function in his series. If it looks like a duck, quacks like a duck and acts like a duck, it doesn't matter if you call it a goose or a chicken, it's a duck.