I also reached out to Canvas, and after running me around in circles for a while they finally gave an answer:
Next step: Assist the user with addressing their request to disable the feature option completely in the ________ School District Canvas instance.
Additional notes: We have provided the instructor with details on the feature option and how this can be rectified. 1. The feature option can be disabled. 2. They can reach out to the tool provider and request they stop sending the data that overwrites these details, we do not have a mechanism that can disable this for tool providers. 3. They can select the tool before adding the assignment name and description that would prevent any content from being overwritten as this only occurs at the time the tool is selected.