My experience has been racking a pumpkin beer is a good idea. At least my pumpkin beers have had a lot of material in the trub that was not your run of the mill yeast, break material, hops, and whatnot trub. I would not want bio material like pumpkin in my beers as I don't think that would age well at all. I know the trend is for primary only fermentation lately, but with fruit beers and spiced beers I really think a secondary is in order. I also think the aging should be done in the secondary carboy to allow for bulk aging. I believe this gives a better flavor profile to beers such as this. Just my .02, take it or leave it.