Quoting: KSIxSKULLS
That's not how it works
In short, here's the chronology of things.
A) Player offers his services to the league at NHL minimum.
B) Agent gets no offers
C) Player picks the team where he wants to be on their taxi squad (Perry and Frolik both choose the Habs).
D) Team (Habs) sign him and put him on waivers.
E) Rest of the league, if they regretted not signing him before, has one last chance to change their mind, but it's only for their regular roster, not their taxi squad.
F) After a day on waivers, no one picks him up because "see point B."
Any team who would pick him up would have to keep him on their 20-23 man roster, so he would count against their cap.
But now, because no one did, the Habs have him and he doesn't even count against the cap. Even when he plays he'll just be replacing someone else's salary, so we basically get both him and Frolik for free.
Well played Marc Bergevin. Well played.