unlikely to be useful unless you're shooting in RAW and need evidence that a specific sensor took the shot. phones and cameras do a lot of post processing before an image hits the disk and the original is discarded.
You wouldn’t need to publish the unprocessed photo, just keep it in escrow.
The new photo would still get signed, and look original.
And if you did this in the right conditions, it wouldn't be possible to tell it was a photo of a print.