Indeed, this matter is not explicitly covered in the style guidelines for titles. Therefore, we need to rely on inference and consensus and, unsurprisingly, different interpretations may exist.
In general, the answer given in this old thread is a good and succinct summary of this consensus. Much more succinct than what I was preparing to type up. 
For similar reasons, as your release does not have any title on the (front/back) cover, I find that the current title is appropriate.