If not, why not?
There is no exact one-word equivalent of the concept of "Freedom" in Ancient Chinese, just as there are no exact one-word equivalent of 仁， 理， 道, etc in Latin, Greek or any Western languages. That's not surprising: it is what makes our world an interesting world of differences.
It doesn't mean Ancient Chinese did not have or need or seek such a thing as Freedom, it means they divided their concepts differently.
In Confucianist context, you could find something related to the freedom of speech in scholars' duty to admonition the ruler when his conduct is improper. Confucius did it himself, at the risk of his life. It could also be said that the confucean emphasis on "Rites" over Laws is a way to define Free will: I do not steal my neighbourgh, not because I fear policemen which force me to obey the laws, but because I have freely accepted and internalized the "Rites" which equates stealing from fellow human beings with a great loss of self-esteem.
In Taoist context, there is an emphasis on spontaneous action done with a free mind, and on a refusal to be "used" (trying to be a twisted tree from which no furniture can be made) which relates to other connotations of our concept of Freedom.
Buddhism has its hole concept of Freedom too, but I know much less about it.
So to answer your "If not, why not", I'd say that the lack of exact one-word equivalent of Freedom in Ancient Chinese do not mean that Chinese culture is missing an essential part. It covers the same human needs, but differently.