Well I think the recent comments about Inception figures shows that HT does consider each costume and how appealing the look of the figure will be. I think they drew the line at the nurse because it'd end up with a niche appeal.
I don't think there's any look to the T-800 that wouldn't have mass Termiantor fan appeal.
Because slight similarities don't stop people from buying, people bought updates a year later of TDK figures. If it looks cool from a property people like, they'll buy.
And same pants and boots isn't much cause to not do it. They can do a new head, and should, as the hair on the damaged head in this set isn't quite right and can be improved, but it can work as a first damaged look. You then have a new tshirt and coat, plust new weapons. Whether they change hair or not from the current BD head, the new one would have the exposed Endo eye and possibly light up feature. The coat would also be tailored to the T-800 body and better fit than sourcing previously sold jackets on the net.