Many fans latched onto this idea partly because it's so insane, and also because the whole 'sins of the father' transcendent storyline seems to be a big themed of Knight, being the Father to Son trailer started with an voiceover of Thomas unknowingly addressing Bruce's career as Batman. So far that's about as far as the theory goes - his voice was a prominent part of the trailer, and has been floated as an idea behind the AK's costume ever since. Chances are if this came true all it would do is infuriate fans of the mythos, as if there's one core thing that remains regardless of who tackles the Batman lore, it's his parents being killed that motivates him to protect Gotham. Thomas' return would no doubt bring up far more questions than it could answer in terms of why he waited multiple decades to return, what he hopes to achieve tackling Bruce without revealing who he is, and even how he's able to fight a guy that's half his age. Definitely one at the bottom of the believability pile for now, but 'never say never' is a popular adage when it comes to second-guessing how writers of comic fiction love to deliver the unexpected, so don't write this off altogether.
