Lost has always been a fantasy show. It has never been a "Robinson Crusoe" type drama. The basic elements coming to fruition now were all introduced by the first three episodes of the first season - the light versus dark game "game", the smoke monster, the walking dead, the whispering in the jungle etc. That was in 2004. I think it is a big stretch to try and claim that they based this on WoA. I have, however, no problems in seeing the similarities, and actually did see quite many of them in the course of earlier seasons. If Sanderson has been an influence on Cuse and Lindelof, I am sure they will acknowledge it, as they have acknowledged plenty of their other inspirations. I just do not think it is the case in a major way, as I believe them when they say that they have "always viewed Lost as a show with a beginning, middle and end". They claim they have known the ending all along, and I am prone to believe them. I think it is much more of a safe bet to say that Sanderson and Lost have touched upon some common themes. It is not as if Sanderson has the copyright on water with healing capabilities, water/nature symbolising the status of a more cosmic struggle, and gods manifesting in the form of black smoke.