most of the time the cc do not seem to budge even when the belts are cycled, so yeah what is the point?
and i have on several occasions during silky smooth flight asked why the belt signs were still on, only to see cc ring the flight deck and bing, belts off. after which a sheepish "they forgot". (at least they were honest and did not come back with some "CAT reported ahead) not blaming or complaining just saying it can happen...