Completely re-making the classification system seems very unnecessary to me. Granted I have no experience of using this for anything outside of this class, but I think that there are fairly specific qualifications for each class, for example any device that sustains life, produces life or death information, or has a largely unknown risk profile will fall under class 3, requiring extensive clinical and safety data. As far as shifting the standard for each class, and adding a class 4, class 5, or any amount of extra classes of risk, I think would only complicate the process of deciding on classification of a device. I think the three classification groups could have some updated qualifications to account for modern day devices. But the system for assessing risk has gotten the job done for many years, and seems that it will continue this way for years to come, so to answer the question, no I do not think there should be more classes added to a new classification system.