Being outspoken and being honest are not the same. Being honest means you tell the truth. Being outspoken means you are not afraid of speaking what you are thinking. The opposite of outspoken is reserved. Examples: I trust Bob because he is honest. Emily is outspoken about her religious beliefs. Laura is not outspoken about her religious beliefs, she is very reserved. John is an outspoken supporter of Japan. To answer your question: being called outspoken is usually not offensive, but it depends a little on the context. Being outspoken about good things (women's rights, etc.) is usually a complement, for example. The synonym "blunt" might be considered more offensive.

Being "outspoken" means you voice your beliefs and opinions with ease. Some synonyms for "outspoken" might be "bold" or "frank". This quality has its place! However, it can be considered offensive when you have no right to be "outspoken". A teacher might not appreciate a student being too "outspoken" about his opinions during class. An employee might be considered too "outspoken" if he voices his complaints to hastily to his employer. Some people consider others too "outspoken" if their thoughts are voiced too often or even too loudly. Some people value a tactful person more than an "outspoken" one. Hope this helps

The term “outspoken” is not at all offensive in the English-speaking world. Now, there may well be some (non-Anglo) cultures that value “social harmony” or “respect for authority” more than the truth, but I wouldn’t know too much about that.