Aye. There is probably a few instances where that wouldn't be the case. Didn't Hiddink come in as a favour to Abramovich, in which he wouldn't leave the club without CL football for the sake of a cup. Same would be for any manager with some sort of connection to the club.
Chelsea might have been better off leaving open the option of him staying on after the season even if they had no plans to keep him whatsoever, though with the way the fans have reacted to him it might not have made any difference anyway.