I don’t even think that is necessarily the case. I reckon that it depends on the AD.
Me: I think my 114060 would look good on an Oysterflex, can you order me one please?
AD: well if you really want one, then yes. But we won’t fit it to your submariner for you, as it isn’t a factory option. You will have to do it yourself.
Me: Thanks, I will let you know if I want one.