How to add a view of product fields to a product display so that it changes when add-to-cart form is updated via ajax?
The fields that change on a product display as different variations are selected on the Add to Cart form are updated via a series of Ajax commands returned by the form's refresh handler. It's about as complicated as the Forms API gets, to be honest, but it lets us do things like render the related fields and return them with instructions to the JavaScript client on where to place the HTML snippets to reflect the updates.

Because your View isn't associated with the product in the same way, you really need to trigger a refresh of its contents yourself. I'm not aware of any modules that will do that for you unless you can try / rule out Views Field. That may work with the product refresh system to support replacing the View alongside other fields.

That said, that's kind of overkill and would require a rearchitecture of your product displays. I would just hook into hook_commerce_cart_attributes_refresh_alter() yourself, re-render the View using the product ID stored in $form['product_id']['#value'], and return a command to drop it into place similar to how the other product fields are updated.