Ikonen was not a wasted pick because you don't know if the kid will stay healthy along the way. And he's the kind of talent you use a pick on. It's unfortunate. But that wasn't a wasted pick.
It's similar to Reway. That kid was a talent worth using a pick on. Health got in the way of his development (and nearly killed him). You may look back and say that was also a wasted pick because the player didn't amount to anything for the organization. But that is definitely the kind of talent you go for.
Walford and Tyszka didn't get signed from the 2017 class, but that is more because the kids didn't progress enough to earn a contract. But out of that 2017 class, Habs drafted, signed, and now have in their pro ranks Poehling, Brook, Fleury, and Primeau.