@Echonic
Scientifically, i think it's impossible now. Since in the previous timeline, he never had sex with any other girls, while in this timeline, he does it quite often, which would alter his set of seeds. Without the exact same seed, he can't have the same child.
And even if a miracle happens and he still got Miyu born, she would still not be the same Miyu that he once had. Due to the rules of causality, a little change in the cause might alter the effect massively: The MC has changed, so his daughter's life and personality could not be the same. Thus the same old Miyu might be considered dead at this moment.
However this is just a manga so maybe i kinda over-analyzed it maybe?