That's pretty much my take on it really, he's unlikely to come in under about 160, he'd probably struggle to make that if he really is munching buckets of KFC
Either the rehydration clause is the issue, as in, the fight is void and called off if he doesn't hit it, or it's a publicity stunt to drag it out and build the hype.
Benn's claiming the weight was decided by Jr's camp too...
I hope it goes ahead in October, it's an intriguing fight. Benn would be daft to agree to much of a higher weight though for obvious reasons. Maybe make it a solid 160 and a rehydration clause of 165.
It's still a disadvantage to Benn but he was always going to be at least a stone lighter anyway so that wouldn't make a huge difference.