Matt Forte's contract expires at the end of the league year, meaning that he may have played his final game in Chicago. However, there is definitely a situation in which he would return to the Bears for 2016.
Sure he's played on some less-than fantastic Bears teams, but he's been a solid contributor, turning out yards and being a reliable, and at times, only offensive weapon the team had at its disposal.
But all good things must come to an end and no where is that more of a reality than in the NFL. It is a business first and foremost and even the best players don't get the storybook ending fans often wish they could see.