Преображенные мифы, VIII - имеем, что у орков не было души. Собственно, там напрямую сказано, что:
In summary: I think it must be assumed that 'talking' is not necessarily the sign of the possession of a 'rational soul' or fëa. The Orcs were beasts of humanized shape (to mock Men and Elves) deliberately perverted / converted into a more close resemblance to Men. Their 'talking' was really reeling off 'records' set in them by Melkor. Even their rebellious critical words - he knew about them. Melkor taught them speech and as they bred they inherited this; and they had just as much independence as have, say, dogs or horses of their human masters. This talking was largely echoic (cf. parrots), in The Lord of the Rings Sauron is said to have devised a language for them.
Свобода воли животного отличается от свободы воли человека. Какая-то свобода воли у орков была, само собой - даже если учитывать иные тексты из десятого тома.