You gotta pay Bell to get him to play.
A 2-3 team with "Superbowl aspirations" aint gonna give him the incentive to risk a bigger payday when the year is over.
That's not quite the case because Bell can't be extended until the offseason based on how the franchise tag works. They could theoretically work out a new 1-year deal in place of the franchise tag, which expires at the end of the league year, but that was only a scenario that would have occurred prior to the season, since he's going to miss approximately half of the season.
It's already been reported that he's coming during the Steelers bye week (7) so he's planning to show up around that time anyway. If he doesn't show up by Week 10 then he forfeits his rights to having accrued an NFL season and is in the same place that he was this year, so he's going to play.
However, the Eagles will absolutely not sign him to a long term contract in the offseason so I'm sure that could muddy the waters a bit with discussions with his agent. I don't think it's going to happen but you never know.
I'd love to get a guy like Coleman and he'd be my number 1 target. I would think the Falcons would be unwilling to let him go because of Freeman's inability to stay on the field consistently, but his contract is up at the end of the year and with all of the injuries to their defense/current level of play, it might make sense for them to get something back for him if they plan to let him walk anyway - although it will need to be a better pick than whatever they'd get for him as a compensatory pick.