It depends on what the advice is on, to be honest. If it is about what to study at university, for example, then yes, this is the teachers' area of specialization and so any advice they offer would probably be well-received. However, if it is personal, I mean, like about home life or relationships, then the teacher needs to be very careful as what they say could land them in trouble. Young people are very impressionable so teachers should stick to what they know, and that's education.