Sometimes teams will make deals in phases. For example, there was a rumor years ago that the Cowboys wanted to sign Peyton Manning and trade Tony Romo. In all likelihood, the Cowboys made phone calls and found a buyer for Romo first, with the idea that if they actually got Manning, they could turn around and deal Romo instantly since a trade would have been put in place beforehand.
Lets say that for arguments sake that the Seahawks are searching the market for a good starting safety. That player is probably going to cost a lot of salary, he'd basically be taking Kam's job permanently. They wouldn't agree to a deal like that unless they already had a buyer lined up for Kam first.
The thing about these two-pronged transactions is that they are notoriously difficult to pull off, and this is why you often hear about how 95% of trade talks fall through and never happen.
It's such a difficult series of moves to pull off, especially with a bit of a pseudo-time limit with the cut deadline only a few hours away, that it's unlikely that Seattle would actually move Chancellor. I'll trust PC/JS whatever they do, but to me, I'd rather have Chancellor miss games then get rid of him forever.
