It's considered poor people meat, in France, in Germany(always was rather regional there, coal mines and steel mills country), Italy also, but there it's doctor prescribed for anemia, and weightlifters eat it for the higher protein.
Breeding for meat has been done for a long time, pretty much all heavy breeds in France are bred thus way, and in Italy, the TPR and Murghese are traditionally bred for meat. Only recently are they being used as driving and riding horses, the latter especially for dressage, since they are a little like Friesians.
The passports: the owner gets to decide if the horse is for human consumption or not, if yes, it can be changed, if not, it can't. The ones declared for human consumption cannot have all medications, and every treatment has to be recorded, signed and stamped by a vet.
Most racehorses are declared not for human consumption, but there are ways to go around that, and they're being slaughtered by the thousands.
As with everything, if there are rules, they're being broken.......