What Shadowblade said.
That's exactly what it means. It will not happen.
Going to the plane of the lost to bargain with the Soul Mother for a strand of someone's soul (who had already permed) would be an insane quest - failure or even success still means instant permadeath for anyone who dies in her domain. It has never been tried in NWN, though there are several characters who have more than considered it. The global return of strands was different, and the result of a successful ECDQ (WL now) - she had a plot and was reaching her hand into the world, and was slapped down, weakened in the process... if it had failed the opposite would probably have occurred, and I bet no one would have liked that. *Looks around.*I'm pretty sure neither of the above were what they were going to implement for strand return, though. Edit - by slapped down, just 'foiled in an indirect manner' - I'm sure if anyone tried to literally slap her down, it would not...go well.