Volk is expecting the rematch, my gut tells me that the UFC and Dana will want to move on.
If Volk can secure the rematch, then power to him, but at the elite level, it's a game of mms, and volk is losing those mms with each passing month.
He should retire, he'll just get KO'd again. If he's going to continue fighting.. he should go bonkers on the TRT, Volk looks a touch less robust in his physique.