It is well known that during a job interview, one should not rant against the previous employer when asked the question why the candidate left the previous job. There are plenty of questions and answers on this very site about it.
However, if one was very happy in a job for several years, but a sudden change in management (boss leaving and being replaced with someone else, company being bought, or some reforms in the company which shifted its culture and goals, etc.) made one unhappy, is it wise to mention it, or should one stick to the bland "looking for new opportunities" answer?
Can a generic "I was happy there for a long time, but there were big changes in management recently which made me concerned" style answer be given without sounding like a rant or a stab at the previous company?