No, the OP is talking about the rare, but increasing number of "multi-airline" check-in machine. I have only seen them in LAS and HPN, but they seem to be increasing in number. These "new" machine serve as check-in for ANY airline.

Apparently, they don't print "FIRST" anywhere on the boarding pass, which prevented the OP from using the TSA premium line. Obviously, the ticket checker (usually NOT employed by TSA) would be looking for something that indicates Elite flyer or First class ticket. They can't possibly be expected to know every plane configuration. I believe a note to the LAS airport authority is warranted.