Originally Posted by
GrandEleven
Why is it now a century early?
If he's moving back in time consistent to his own timeline ... why would anything change? The only real timeline mangle comes from CW2 but then that story mangled everything, so just take that at face value.
In other words, he's not moving back in time and staying in this universe ... he's moving back in his own timeline which means he effectively crosses multiverses. That's the whole reason he expects to run into the baby: if he stayed consistent in this universe he could never make it back to that point. I fact it would have been a fun opportunity to make subtle changes to help underscore this as it was effectively a different universe, but sadly we never saw that.