Yeah, once you eliminate travelling from Earth-2 to Earth-1 it's easier to incorporate the mother/daughter bit. Having a childless Dinah from Earth-2 coming to Earth-1 and then inventing Canary suddenly having had a daughter with her now dead husband back when she was still on Earth-2 becomes a bit more complicated.
As for the "weird" part of the origin retcon, they had to explain why Black Canary had all these memories / references to her late husband while she had been on Earth-1 in previous stories.