I'm not sure that butchers, in the western world at least, have ever used wooden knives. There are wooden knives, made from hickory, ebony, rosewood or beech, to name only a few, that are used for a variety of purposes. Eastern 'butchers' would often use knives fashioned from local wood. Bakers still use a wooden knife for cutting dough. Once again this could be made from any number of woods.