I am not really sure whether I believe that article at all especially when talking about players outside of the top 10 being 3rd or 4th liners.
From my rankings, all of these players are projected outside the top 10 and all own top 6 upside or top 4 defensemen upside:
Rasmus Ristolainen (top pairing), Erne (2nd line), Max Domi (1st line), Ryan Pulock (top 4), Frederik Gauthier (2nd line), Bo Horvat (2nd line), Mantha (2nd line), Dickinson (1st line), Wennberg (1st line), Petan (1st line), Justin Bailey (1st line), Slepyshev (1st line), plus many many more.
I agree that there are some players who project as bottom-6 types inside the top 60 (Hartman, Lazar, de la Rose, etc.) but if you can get those types in the late 1st or early 2nd then I am sure any NHL team would be happy.
Outside of the 2nd round, it's a crapshoot...it always is. This is the area where teams take their shots at homeruns or personal favourites.