The company took away my title of Operations Manager and my managerial authority over key functions and personal and made me responsible for special projects. I have been employed with this company for 31 years, 9 of those years as Operations Manager, overseeing our Canadian warehouses, Customer service, purchasing, Canada customs, etc. What are my rights under constructive dismissal

The company is not entitled to demote you (unless it is a very minor change). Such a demotion may result in a constructive dismissal which would allow you to leave and still get your full severance. In your case, this would be 24 months compensation. The thing about a constructive dismissal is that if you stay in the new role, you are considered to have accepted the change, and then it is too late to do anything. You have to respond very quickly here. That is why it is important that we speak right away. Please do not do anything before we speak. My number is below.