No, that is not guaranteed. Look at how many people regard the eighth-overall picks already on the team or already traded (Nylander, Ristolainen, Mittelstadt). And then look at Derrick Pouliot, Alexander Burmistrov, and others. Not exactly a guarantee. Even first overall isn't guaranteed, as Alexandre Daigle might remind you, or third (Gratton, same draft) or fifth (Rob Niedermayer, same draft). You know what IS guaranteed? An actual NHL player.