I have news for you, everything about demand of items going up is all "Speculation".
Let's see what google has to say about speculation: "define: Speculation"
it essentially say's, it's a guess and not 100% fact.
Which mean's there's no 100% proof that ghost iron ore/living steel/trillium bars will go up in such a high price that there's enough room to sell all your stock pile and profit off it $$$$.
When it come's to stockpiling, don't just stock pile for a patch, stock pile for your professions with items that you use often.
There's no point in stockpiling unless you yourself/your professions can benefit from it.
Think of it this way, if everyone stock piles ghost iron and they have no profession's that use it and they all sell on the AH during patch drop... there's gonna be a flood, everyone undercutting which means your profits will potentially be a loss.
But i already bought it all :(Sure, hold onto what you already bought don't flood at patch drop disperse it between bars/ore and wait for prices to even out and hopefully they even out on a profit!
Worse comes worse, find someone to craft gear for you with the ore! I'm sure a guildy wouldn't mind helping out a friend!
But for now....