Can Product Management get by without being a super user of their product?

Not in my experience!

The Product Team must know how to use the products and what the value is for each feature. How can you have meaningful conversation with customers if you do not understand what they are talking about? How can you talk to analysts and the press if you don't know the product and it value?

Sometimes, customers do not know how to use a feature and are not really asking for new functionality. It would be a great loss of time to try to implement a new feature that already exists. This happens more than you would think. The development teams know their code very well, but sometimes another team will unknowingly create similar features. This is a drag on productivity and costs time and money that wasn't needed. The product teams must know what and why the features exist. This takes communication and collaboration.