I think it comes to a question of cost/benefit. Dealing with Roc Nation or whatever enterprise that has Jay Z's catalog for just an EP with barely any additional stuff, with the risk of being a commercial failure, isn't worth.
LP hardcore fan base isn't so big as some people of this forum think. Yeah, Numb/Encore is quite popular, but nobody remember the remaining tracks.
Besides, best case scenario, what can you throw on an hypothetical edition? The Roxy, Live 8 show and the MFR 05? That shit fits on one single DVD and it's just for us.