Willy is the kind of player you keep for life. Drafted and developed, has been a star from the outset, is the most clutch guy among them in the playoffs, can handle the media in his sleep, and consistently commits long term. They would be morons to deal him, and I don't care pretty much who they're getting that isn't named McDavid or Celebrini.
Knies is just scratching the surface and an argument could be made that he's the hardest type of player to acquire outside of drafting him. He has also been a dedicated team guy - vocal, unlike the other AZ boy - has gotten better each year, and is signed long term for cheap. We haven't even started to see what he can do yet.
They'd be so foolish to part with either of them. I would legit, no kidding around, be shopping Matthews first before those two, since he could be an injured shell of himself for the rest of his career, is only signed for two more years, and is apparently on the fence about staying. You could get the best return for him, even with his recent diminished performances, and build in a big way around Willy, Knies, McKenna, and Cowan. Again, not that I want them to go out and try to trade him, specifically because of his down years due to injury, but if forced to deal one, he's definitely not off the table for me.
The reality is, they don't need to part with any of them, and they shouldn't. Keep trying to grab good players without losing your own. Draft, sneaky trades, etc. Montreal got Hutson in the second round. Raddysh came out of nowhere and could be had for free. There's so many better ways to get better than taking a dumb risk and trading your most valuable assets. It's just a wrongheaded backwards method of teambuilding that only a lazy dummy would resort to because they lack the capacity to move creatively.