I'm having the same issue, but I found a way around it for the meantime. I edit the mask element and chenge its type to something else—like Text—where I can set the title. After typing the title I save it, then change back to mask element and save again. This works by me without losing the content of the mask element. This way I can see the title in typo3 backend when I view as list or page or add content from another page. As I said, it doesn't solve the problem, but can help until there is a proper solution.
EDIT
I've just found another solution. You can add the title field to en existing mask element. To do it, go to ADMIN TOOLS > Mask, click your mask element to edit it. Add a new item by dragging the item (the one on top of the list of available items) to the right where your items are. Then in General under dropdown choose an named:
: ()
Save, close, go to your page to add your title. This still doesn't add the title field automatically to all mask elements, but it is a step forward.
