My money would be on losing Graves to expansion before we lose him to any contract related issues.
Make no mistake about it, the dude was a legit Top 4 Defender this past season. You dont put up almost 10 Goals and 30 points, and play ~19 minutes a night as a bottom pairing Defender.
But... With Girard and Makar certainly being protected in expansion, and tentatively EJ needing protection, as well as the unknown of Timmins expansion status, there's a pretty good chance Graves will be exposed for Seattle and I dont see how they dont take him, assuming he has another good year next year at least. You're looking at a big, mobile defender with a booming shot that can kill penalties, is solid defensively, and competent enough offensively to make his shot a legit weapon on the ice. That's a very valuable player(Oddly enough it is basically exactly what the Avs hoped Zadorov would develop into).