There's some chatter that he may sign a new deal now. Most likely with some kind of release clause or something else that gets him out next season.
There very well could have been some kind of Gentlemen's agreement, however, it may have been he could go if someone bids what he's worth and no one did. We'll never know the ins and outs, it's all speculation. But Kane should have put whatever it was in writing. Signed a new deal last year with a release clause or player option to opt out, etc. Using his brother for his agent is a huge mistake because he was way out of his depth.