Do you think that after this war the villages will start a tradition of sealing powerful ninjas who have past away? Just a random thought, I don't know if being sealed is a disrespectful thing to the dead but just thinking.
i dont think so,its alot easier to kill the users of the technique before they pass the into another generation.
curently there is only 2 known users...kabuto and tobi(theoredicaly)
only the leaf hokages are in the demons stomach, the rest are bounded in some toilet paper cocoon sealing jutsu. me wonders if kabuto will physically cancel the jutsu or if killing him will cancel it. if it doesnt then woulnt itachi and the rest end up as zombies for eternity?