It's already been confirmed, to my annoyance, that it will be in the matte rather than the actual picture. There was some interview referred to in the making of the '93 transfer that stated they had to go back to original elements before the subtitles were "burned in." I really prefer the subtitles in the actual frame. It just doesn't seem right to me that they should be outside elements that are digitally inserted in a black void that's not at all part of the movie, and that's the one thing about all my DVDs that I just have to do my best to ignore.

EDIT: I missed part of your question. On a 16x9, it most likely will be in the frame of the movie, even though it's still not actually part of the film element. On a standard TV, it will definitely be in the matte.