I'm sure his agent has already estimated his market value. And maybe I'm wrong but I believe he would have to actually void his contract before other teams could actually start talking to his agent about offering him a contract. Not sure how any of this plays out considering this (if I'm right).
If he voids his contract right away though, I'd say it definitely would suggest he will be aggressively exploring free agency. If he doesn't, it may mean that he is close to working out a deal so why bother. Even if he voids the contract quickly, I don't think it means that he will get a better offer elsewhere.
I too would hate to see him wearing another jersey. But if it happens, I'm not going to start a rant about who screwed up, or is cheap, or was just looking for a payday. SJ is a stud and a class act. KC has generally done what he said he would. These are not the days of Ziggy, Shaw, and the Showgirl. We have actual football minds running the show and an owner that will invest in smart moves.
All that said, I think he finishes his career in horns under a four year deal that is cap friendly while paying him some sort of guaranteed money that works for both sides in case he is only productive for another year or two.