Why did Thomas die?

[Spoiler: s3e10]

We found out that Jade and Tabitha kept reincarnating so they can save the children and that one of them was their daughter. But what if they also had a son? Because we mainly see two kids following Tabi, a girl and a boy. And then the girl kneels next to her and she remembers. But nothing more than that was said because she was too shocked from remembering.

I have a strange theory that maybe the reason Thomas died is because Tabitha and Jade were meant to have two kids originally and each time only two kids were born. Jade doesn't have kids but Tabi has two. Miranda had two kids and Christopher didn't (i think, maybe he did and my theory is stupid). So the reason Thomas died is because he was a glitch in the whole system and a third child wasn't supposed to be born.

P.S. i'm so bored and i need answers, idk how i'll wait until 2026