It would be absolutely stunning if the law gives them any rights at all.

One can hope that the updated legislation somehow addresses this. That said, it would be absolutely stunning if the previously existing law didn't simply go 'boink!' in the face of a heretofore novel circumstance. At very least, I could see the need for the courts to set a precedent if/when the first case came along.

I guess it isn't that novel anymore for a woman to donate eggs and not expect to have any rights to any resulting children.

Swapping out the nuclear DNA doesn't really complicate that.

I believe the proposals state that the mitochondrial donor has no legal rights in regards to the child.

See my comment elsewhere with regard to the question of what the child's rights might be.

As I understand it they have the same rights as an organ or blood donor - none.