The past is prologue...what I think will happen next year is that there will be a hoard of people who watched last year's SW advent or have been watching this year's SW advent skyrocket and, as a result, will conclude that next year's advent will be a sure-fire winner that couldn't possibly lose, which will lead them to buy heavily into next year's edition. Meanwhile, having watched how inventory levels for this year's edition fared, the smart folks at TLG will conclude that they distributed too few advents this year and will adjust their distribution numbers upwards, which will leave the sets in the stores longer and squeeze the window of time in which resellers could take advantage of inventory shortfalls. Then, when all of the resellers go to sell, they will find that it's more difficult to sell all of the extra sets that they have put back and prices won't climb as high or as fast as they assumed they would.
All just speculation, but, in my experience, assuming that a seasonal set will perform simply because an earlier one did is much more of a gamble than it seems. The SW advents have performed well each of the last two years, but go back and look at how the two editions before those performed...it's a very different picture.