Yeah, it's a meticulously crafted game and even though logic gate puzzles can be intricate to craft it's not something I would expect Tonda Ros to miss. And you know... there are a lot of genuinely brilliant and slightly crazy people in the Blue Prince community. If there actually was an oversight in there, we would have known about it by now.
Coincidentally, there was actually an oversight in another late game puzzle, and it was of course found. I don't know if it's been patched.
late game spoiler, don't click unless you're confident you're done with the game
There was one word in the numbered cores puzzle from the secret lockbox in the vault that could actually be solved into two different letters.