Exactly. You cant be high risk and be #2 or #3 overall. It doesnt mean you have high potential. High risk implies that a player has several major deficiencies (or off ice issues) that may withhold him from making it to the NHL. Typically these players are really good at certain skills, but also have red flags. Think Kaliyev. One of the best shooters outside the NHL, but has major defensive holes that he must overcome if he ever wants to make it in the NHL. Byfield has high potential, and has small holes in his game.
When I think "safe prospects" I think players who have a high likelihood of being productive in the NHL. This doesnt mean best player in his draft class. Typically, I look at players closer to their full potential. In this draft, I would say those players are Lafreniere and Rossi. Both players who have a well rounded game and won't be bottom liners. Both are reasonably expected to be with their NHL clubs next season. I could also argue Sanderson, who plays a very steady game even though he is 1-2 years away.
Byfield, Stutzle, Raymond, Perfetti, Drysdale, Holtz, Lundell, etc. would not be considered safe prospects or high risk prospects. It's not one or the other.