...when it comes to popular and 'smaller production' references like
5004, 5970, 10 Day TB. SkyMoon TB etc.
I believe that they only want to make sure that the watch is being purchased
by someone who will actually wear it - and not a gray market dealer.
(As such I see the practice being pretty resonable).
_See Rolex Wallpapers & Technical Data about most current Rolex models: HERE_