People were selling them for ludicrous amounts ($50) on eBay over here, so at a guess, people want them and
GW don't like that resale culture.
Also there was no PDF of the chart. My copy and the one I photographed before #66 are the only ones I've heard of that made it online.
Of course i could be wrong, and
GW are redoing the paint line with substitutions, with no prior notice.