Let's just say it was Kane, he'd have to waive his NMC. I guess that's possible but seems unlikely. And it's probably something you'd figure out earlier than the 11th hour and definitely before info leaks out that could leak names involved in a trade from your side.
But if it were going to be Kane, who you'd have for three more years after this one, then - in theory - you'd be comfortable trying to win a cup with Varly, who's also signed three more years.
In fact, the next 3 years really would be the window for the Isles with a guy like Kane. The rest of the core, outside of Barzy, Tito and some of the dmen, would all be best served by having their best shot before 2023-24 season. Even the young guys like Barzy, etc. would be best served with that window (at least on this team).
For Chicago, it'd mean rejiggering for a run starting in earnest in 2022-23. You'd see players shipped out and young talent brought in. Sorokin projects be a solid top net minder (if not necessarily top 5) for the next 10 years, with upside to be elite. On that 22-23 and forward timeline, this trade works out well for the Hawks, too.